From 2ebaafb7d9fb05110885af507b66fc9938945c67 Mon Sep 17 00:00:00 2001
From: Justin Ridgewell <justin@ridgewell.name>
Date: Thu, 17 May 2018 22:22:19 -0400
Subject: [PATCH] Update fixtures

---
 .../test/fixtures/regression/6154/output.js                   | 4 ++--
 .../test/fixtures/regression/7030/output.js                   | 4 ++--
 .../test/fixtures/extend-builtins/loose/output.js             | 4 ++--
 .../test/fixtures/extend-builtins/spec/output.js              | 4 ++--
 .../call-semantics-data-defined-on-parent/output.js           | 2 +-
 .../call-semantics-getter-defined-on-parent/output.js         | 2 +-
 .../call-semantics-not-defined-on-parent/output.js            | 2 +-
 .../call-semantics-setter-defined-on-parent/output.js         | 2 +-
 .../get-semantics-data-defined-on-parent/output.js            | 2 +-
 .../get-semantics-getter-defined-on-parent/output.js          | 2 +-
 .../get-semantics-not-defined-on-parent/output.js             | 2 +-
 .../get-semantics-setter-defined-on-parent/output.js          | 2 +-
 .../test/fixtures/get-set-loose/memoized-assign/output.js     | 2 +-
 .../test/fixtures/get-set-loose/memoized-update/output.js     | 2 +-
 .../set-semantics-data-defined-on-parent/output.js            | 2 +-
 .../set-semantics-getter-defined-on-parent/output.js          | 2 +-
 .../set-semantics-not-defined-on-parent-data-on-obj/output.js | 2 +-
 .../output.js                                                 | 2 +-
 .../set-semantics-not-defined-on-parent-not-on-obj/output.js  | 2 +-
 .../output.js                                                 | 2 +-
 .../set-semantics-setter-defined-on-parent/output.js          | 2 +-
 .../get-set/call-semantics-data-defined-on-parent/output.js   | 4 ++--
 .../get-set/call-semantics-getter-defined-on-parent/output.js | 4 ++--
 .../get-set/call-semantics-not-defined-on-parent/output.js    | 4 ++--
 .../get-set/call-semantics-setter-defined-on-parent/output.js | 4 ++--
 .../get-set/get-semantics-data-defined-on-parent/output.js    | 4 ++--
 .../get-set/get-semantics-getter-defined-on-parent/output.js  | 4 ++--
 .../get-set/get-semantics-not-defined-on-parent/output.js     | 4 ++--
 .../get-set/get-semantics-setter-defined-on-parent/output.js  | 4 ++--
 .../test/fixtures/get-set/memoized-assign/output.js           | 4 ++--
 .../test/fixtures/get-set/memoized-update/output.js           | 4 ++--
 .../get-set/set-semantics-data-defined-on-parent/output.js    | 4 ++--
 .../get-set/set-semantics-getter-defined-on-parent/output.js  | 4 ++--
 .../set-semantics-not-defined-on-parent-data-on-obj/output.js | 4 ++--
 .../output.js                                                 | 4 ++--
 .../set-semantics-not-defined-on-parent-not-on-obj/output.js  | 4 ++--
 .../output.js                                                 | 4 ++--
 .../get-set/set-semantics-setter-defined-on-parent/output.js  | 4 ++--
 .../fixtures/loose-classCallCheck/with-superClass/output.js   | 2 +-
 .../test/fixtures/regression/T7537/output.js                  | 4 ++--
 .../spec/super-reference-before-bare-super-inline/output.js   | 4 ++--
 .../fixtures/spec/super-reference-before-bare-super/output.js | 4 ++--
 .../test/fixtures/regression/4349/output.js                   | 2 +-
 .../get-set/get-semantics-data-defined-on-parent/output.js    | 2 +-
 .../get-set/get-semantics-getter-defined-on-parent/output.js  | 2 +-
 .../get-set/get-semantics-not-defined-on-parent/output.js     | 2 +-
 .../get-set/get-semantics-setter-defined-on-parent/output.js  | 2 +-
 .../get-set/set-semantics-data-defined-on-parent/output.js    | 2 +-
 .../get-set/set-semantics-getter-defined-on-parent/output.js  | 2 +-
 .../output.js                                                 | 2 +-
 .../output.js                                                 | 2 +-
 .../output.js                                                 | 2 +-
 .../set-semantics-not-defined-on-parent-data-on-obj/output.js | 2 +-
 .../output.js                                                 | 2 +-
 .../set-semantics-not-defined-on-parent-not-on-obj/output.js  | 2 +-
 .../output.js                                                 | 2 +-
 .../get-set/set-semantics-setter-defined-on-parent/output.js  | 2 +-
 .../test/fixtures/object-super/super-exponentiation/output.js | 2 +-
 .../test/fixtures/regression/6057-expanded/output.js          | 4 ++--
 .../test/fixtures/plugins-integration/issue-7527/output.js    | 4 ++--
 60 files changed, 86 insertions(+), 86 deletions(-)

diff --git a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js
index d3fda01fd7dc..a07bdd49c0b3 100644
--- a/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js
+++ b/packages/babel-plugin-proposal-class-properties/test/fixtures/regression/6154/output.js
@@ -4,7 +4,7 @@ function _instanceof(left, right) { if (right != null && typeof Symbol !== "unde
 
 function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
@@ -18,7 +18,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var Test = function Test() {
   "use strict";
diff --git a/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/output.js b/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/output.js
index aa7a196e2644..64009cae8ad7 100644
--- a/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/output.js
+++ b/packages/babel-plugin-proposal-decorators/test/fixtures/regression/7030/output.js
@@ -8,9 +8,9 @@ function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) ===
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/loose/output.js b/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/loose/output.js
index 87c2fb2f4bf7..a185a6d10e24 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/loose/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/loose/output.js
@@ -1,4 +1,4 @@
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _wrapNativeSuper(Class) { var _cache = typeof Map === "function" ? new Map() : undefined; _wrapNativeSuper = function _wrapNativeSuper(Class) { if (Class === null) return null; if (typeof Class !== "function") { throw new TypeError("Super expression must either be null or a function"); } if (typeof _cache !== "undefined") { if (_cache.has(Class)) return _cache.get(Class); _cache.set(Class, Wrapper); } function Wrapper() { return _construct(Class, arguments, _getPrototypeOf(this).constructor); } Wrapper.prototype = Object.create(Class.prototype, { constructor: { value: Wrapper, enumerable: false, writable: true, configurable: true } }); return _setPrototypeOf(Wrapper, Class); }; return _wrapNativeSuper(Class); }
 
@@ -8,7 +8,7 @@ function _construct(Parent, args, Class) { if (isNativeReflectConstruct()) { _co
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var List =
 /*#__PURE__*/
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/spec/output.js b/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/spec/output.js
index 6db28c672d62..327d87f46469 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/spec/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/extend-builtins/spec/output.js
@@ -4,7 +4,7 @@ function _possibleConstructorReturn(self, call) { if (call && (typeof call === "
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _wrapNativeSuper(Class) { var _cache = typeof Map === "function" ? new Map() : undefined; _wrapNativeSuper = function _wrapNativeSuper(Class) { if (Class === null) return null; if (typeof Class !== "function") { throw new TypeError("Super expression must either be null or a function"); } if (typeof _cache !== "undefined") { if (_cache.has(Class)) return _cache.get(Class); _cache.set(Class, Wrapper); } function Wrapper() { return _construct(Class, arguments, _getPrototypeOf(this).constructor); } Wrapper.prototype = Object.create(Class.prototype, { constructor: { value: Wrapper, enumerable: false, writable: true, configurable: true } }); return _setPrototypeOf(Wrapper, Class); }; return _wrapNativeSuper(Class); }
 
@@ -14,7 +14,7 @@ function _construct(Parent, args, Class) { if (isNativeReflectConstruct()) { _co
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var List =
 /*#__PURE__*/
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-data-defined-on-parent/output.js
index ee6d7888aaa6..749d41bcb908 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-data-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base =
 /*#__PURE__*/
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-getter-defined-on-parent/output.js
index e221a210b240..8dcb819aa2bc 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-getter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-not-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-not-defined-on-parent/output.js
index 19a5133e9a66..75ec984edfbb 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-not-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-not-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-setter-defined-on-parent/output.js
index 002192c52d83..908eb7ca5232 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/call-semantics-setter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-data-defined-on-parent/output.js
index 9526f8a361db..8a3fc0f48b68 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-data-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-getter-defined-on-parent/output.js
index 36ab29407fd2..1902097466e1 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-getter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-not-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-not-defined-on-parent/output.js
index 9880bfe11307..555608972524 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-not-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-not-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-setter-defined-on-parent/output.js
index 4e03f7e9fcfa..7fc7d3b18071 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/get-semantics-setter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-assign/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-assign/output.js
index 10536326298b..2fee4d6c0af3 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-assign/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-assign/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-update/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-update/output.js
index eaeea288da15..e8fa9cdaa6fe 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-update/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/memoized-update/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-data-defined-on-parent/output.js
index 498198dd54ee..3643eed61d25 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-data-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-getter-defined-on-parent/output.js
index 27c87b612321..5bcc7f094e98 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-getter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-data-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-data-on-obj/output.js
index 639eba6cc16c..0d97a8d0b6c4 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-data-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-data-on-obj/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-getter-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-getter-on-obj/output.js
index e66fd7e19178..b3b826bffb5d 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-getter-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-getter-on-obj/output.js
@@ -4,7 +4,7 @@ function _defineProperties(target, props) { for (var i = 0; i < props.length; i+
 
 function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-not-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-not-on-obj/output.js
index c5cb38d3efee..517190536f13 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-not-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-not-on-obj/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-setter-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-setter-on-obj/output.js
index 583f064e8679..3f9008f275ac 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-setter-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-not-defined-on-parent-setter-on-obj/output.js
@@ -4,7 +4,7 @@ function _defineProperties(target, props) { for (var i = 0; i < props.length; i+
 
 function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let Base = function Base() {};
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-setter-defined-on-parent/output.js
index 271a214803b7..901716ff45dd 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set-loose/set-semantics-setter-defined-on-parent/output.js
@@ -1,6 +1,6 @@
 "use strict";
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-data-defined-on-parent/output.js
index 4d165ec4e463..f24925f44e18 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-data-defined-on-parent/output.js
@@ -8,9 +8,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-getter-defined-on-parent/output.js
index 7091c909b689..67ea1515af9e 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-getter-defined-on-parent/output.js
@@ -8,9 +8,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-not-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-not-defined-on-parent/output.js
index 63f653a56668..402c290e2b95 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-not-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-not-defined-on-parent/output.js
@@ -12,9 +12,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-setter-defined-on-parent/output.js
index d607d2f86048..3cf816ef56f0 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/call-semantics-setter-defined-on-parent/output.js
@@ -8,9 +8,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
index 943986b2af07..7c5baa698586 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
@@ -12,9 +12,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
index a681a705b3b5..b9d31d8fdd19 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
@@ -8,9 +8,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
index 1a06ef6e3ea4..73ac7171cf50 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
@@ -12,9 +12,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
index 5ea0847b12d5..69aa746e0f6e 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
@@ -8,9 +8,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-assign/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-assign/output.js
index e978c9e9c9e4..7c63b820e3a1 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-assign/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-assign/output.js
@@ -18,9 +18,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-update/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-update/output.js
index 10230c56a35e..ba36fa5335c2 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-update/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/memoized-update/output.js
@@ -18,9 +18,9 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
index e74d989aed29..17aa7df460ff 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
@@ -16,9 +16,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
index 6ba80ae35d49..9abfa1053cb7 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
@@ -12,9 +12,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
index 10f3c4886f43..7c0202db3e14 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
@@ -16,9 +16,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
index ccc1061ecca7..f7f87b6f1981 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
@@ -16,9 +16,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
index 618f48e8554e..224739daa9f8 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
@@ -16,9 +16,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
index 9386b2682624..b2babf0fb445 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
@@ -16,9 +16,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
index d47916df7584..1483e54ab168 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
@@ -12,9 +12,9 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/loose-classCallCheck/with-superClass/output.js b/packages/babel-plugin-transform-classes/test/fixtures/loose-classCallCheck/with-superClass/output.js
index 7dfbc2cda9e9..75e2ab5c8728 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/loose-classCallCheck/with-superClass/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/loose-classCallCheck/with-superClass/output.js
@@ -1,6 +1,6 @@
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
+function _inheritsLoose(subClass, superClass) { subClass.prototype.__proto__ = superClass && superClass.prototype; subClass.__proto__ = superClass; }
 
 let B = function B() {
   "use strict";
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/regression/T7537/output.js b/packages/babel-plugin-transform-classes/test/fixtures/regression/T7537/output.js
index d9ca778729b1..88bcd6788f45 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/regression/T7537/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/regression/T7537/output.js
@@ -4,9 +4,9 @@ function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) ===
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super-inline/output.js b/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super-inline/output.js
index 61313be50dfb..892c96bd2b8f 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super-inline/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super-inline/output.js
@@ -4,7 +4,7 @@ function _possibleConstructorReturn(self, call) { if (call && (typeof call === "
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
@@ -12,7 +12,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var Foo =
 /*#__PURE__*/
diff --git a/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super/output.js b/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super/output.js
index a50ed990c50c..27a80bb83814 100644
--- a/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super/output.js
+++ b/packages/babel-plugin-transform-classes/test/fixtures/spec/super-reference-before-bare-super/output.js
@@ -4,7 +4,7 @@ function _possibleConstructorReturn(self, call) { if (call && (typeof call === "
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
@@ -12,7 +12,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var Foo =
 /*#__PURE__*/
diff --git a/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4349/output.js b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4349/output.js
index e8e715b61627..d6afbaa7f07c 100644
--- a/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4349/output.js
+++ b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4349/output.js
@@ -10,7 +10,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 foo = _obj = {
   bar() {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
index d36b21708598..451ffe5dabba 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-data-defined-on-parent/output.js
@@ -6,7 +6,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {
   test: 1
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
index 3145be482ff1..1b126b146f9b 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-getter-defined-on-parent/output.js
@@ -6,7 +6,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {
   get test() {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
index ffcfc54cb2d9..bc77e38b766b 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-not-defined-on-parent/output.js
@@ -6,7 +6,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
index a764ffde6a7c..410f0fa63254 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/get-semantics-setter-defined-on-parent/output.js
@@ -6,7 +6,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {
   set test(v) {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
index 388e2cde397e..a69326d4f1a1 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-data-defined-on-parent/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {
   test: 1
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
index 7cda93dd0449..f915f65c6476 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-getter-defined-on-parent/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {
   get test() {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-configurable-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-configurable-on-obj/output.js
index 1723818e082b..2104fb5caf9a 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-configurable-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-configurable-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-enumerable-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-enumerable-on-obj/output.js
index a7e39d878c1e..fb14ed543283 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-enumerable-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-enumerable-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-writable-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-writable-on-obj/output.js
index 45ff9759719d..8569385fb026 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-writable-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-non-writable-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
index 9b0e76fca9b9..36334db5fd41 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-data-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
index df83002f3632..4378ee394bf6 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-getter-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
index e6c90419f085..1e251942ecaa 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-not-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 const obj = _obj = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
index 3c1c3278a125..349436fd9e7a 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-not-defined-on-parent-setter-on-obj/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 const Base = {};
 let value = 2;
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
index 6c1471fa6051..344a8e3a107b 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/get-set/set-semantics-setter-defined-on-parent/output.js
@@ -10,7 +10,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 let value = 1;
 const Base = {
diff --git a/packages/babel-plugin-transform-object-super/test/fixtures/object-super/super-exponentiation/output.js b/packages/babel-plugin-transform-object-super/test/fixtures/object-super/super-exponentiation/output.js
index cf1162d608b7..0fd29f8a9f82 100644
--- a/packages/babel-plugin-transform-object-super/test/fixtures/object-super/super-exponentiation/output.js
+++ b/packages/babel-plugin-transform-object-super/test/fixtures/object-super/super-exponentiation/output.js
@@ -10,7 +10,7 @@ function _get(target, property, receiver) { if (typeof Reflect !== "undefined" &
 
 function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 foo = _obj = {
   bar: function () {
diff --git a/packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js b/packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js
index 710638e540e6..d9b6dc716df1 100644
--- a/packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js
+++ b/packages/babel-plugin-transform-parameters/test/fixtures/regression/6057-expanded/output.js
@@ -21,9 +21,9 @@ function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _d
 
 function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
diff --git a/packages/babel-preset-env/test/fixtures/plugins-integration/issue-7527/output.js b/packages/babel-preset-env/test/fixtures/plugins-integration/issue-7527/output.js
index 93e329010fce..c4b46414ee70 100644
--- a/packages/babel-preset-env/test/fixtures/plugins-integration/issue-7527/output.js
+++ b/packages/babel-preset-env/test/fixtures/plugins-integration/issue-7527/output.js
@@ -8,7 +8,7 @@ function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) ===
 
 function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
 
-function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } _setPrototypeOf(subClass.prototype, superClass && superClass.prototype); if (superClass) _setPrototypeOf(subClass, superClass); }
 
 function _wrapNativeSuper(Class) { var _cache = typeof Map === "function" ? new Map() : undefined; _wrapNativeSuper = function _wrapNativeSuper(Class) { if (Class === null) return null; if (typeof Class !== "function") { throw new TypeError("Super expression must either be null or a function"); } if (typeof _cache !== "undefined") { if (_cache.has(Class)) return _cache.get(Class); _cache.set(Class, Wrapper); } function Wrapper() { return _construct(Class, arguments, _getPrototypeOf(this).constructor); } Wrapper.prototype = Object.create(Class.prototype, { constructor: { value: Wrapper, enumerable: false, writable: true, configurable: true } }); return _setPrototypeOf(Wrapper, Class); }; return _wrapNativeSuper(Class); }
 
@@ -18,7 +18,7 @@ function _construct(Parent, args, Class) { if (isNativeReflectConstruct()) { _co
 
 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
 
-function _getPrototypeOf(o) { _getPrototypeOf = Object.getPrototypeOf || function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__; }; return _getPrototypeOf(o); }
 
 var MyDate =
 /*#__PURE__*/