diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 380be73b482d7..998253d6e4fde 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -3628,13 +3628,13 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                     // only allow export default at a source file level
                     if (modulekind === ModuleKind.CommonJS || modulekind === ModuleKind.AMD || modulekind === ModuleKind.UMD) {
                         if (!isEs6Module) {
-                            if (languageVersion === ScriptTarget.ES5) {
-                                // default value of configurable, enumerable, writable are `false`.
-                                write("Object.defineProperty(exports, \"__esModule\", { value: true });");
+                            if (languageVersion === ScriptTarget.ES3) {
+                                write("exports.__esModule = true;");
                                 writeLine();
                             }
-                            else if (languageVersion === ScriptTarget.ES3) {
-                                write("exports.__esModule = true;");
+                            else {
+                                // default value of configurable, enumerable, writable are `false`.
+                                write("Object.defineProperty(exports, \"__esModule\", { value: true });");
                                 writeLine();
                             }
                         }
@@ -5190,6 +5190,8 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         write(`exports.default = `);
                         emitDeclarationName(node);
                         write(";");
+                        writeLine();
+                        emitEs6ExportDefaultCompat(node);
                     }
                 }
                 else if (node.parent.kind !== SyntaxKind.SourceFile || (modulekind !== ModuleKind.ES6 && !(node.flags & NodeFlags.Default))) {
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 280b8203ff458..95bf4ff7fa32b 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2400,7 +2400,7 @@ namespace ts {
      * Serialize an object graph into a JSON string. This is intended only for use on an acyclic graph
      * as the fallback implementation does not check for circular references by default.
      */
-    export const stringify: (value: any) => string = JSON && JSON.stringify
+    export const stringify: (value: any) => string = typeof JSON !== "undefined" && JSON.stringify
         ? JSON.stringify
         : stringifyFallback;
 
diff --git a/tests/baselines/reference/anonymousDefaultExportsAmd.js b/tests/baselines/reference/anonymousDefaultExportsAmd.js
index 67931fd6cc871..9074f0f71fd78 100644
--- a/tests/baselines/reference/anonymousDefaultExportsAmd.js
+++ b/tests/baselines/reference/anonymousDefaultExportsAmd.js
@@ -12,10 +12,12 @@ define(["require", "exports"], function (require, exports) {
     class default_1 {
     }
     exports.default = default_1;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 define(["require", "exports"], function (require, exports) {
     "use strict";
     function default_1() { }
+    Object.defineProperty(exports, "__esModule", { value: true });
     exports.default = default_1;
 });
diff --git a/tests/baselines/reference/anonymousDefaultExportsCommonjs.js b/tests/baselines/reference/anonymousDefaultExportsCommonjs.js
index 513b75c27bdd3..b5f7dbff9fae3 100644
--- a/tests/baselines/reference/anonymousDefaultExportsCommonjs.js
+++ b/tests/baselines/reference/anonymousDefaultExportsCommonjs.js
@@ -11,7 +11,9 @@ export default function() {}
 class default_1 {
 }
 exports.default = default_1;
+Object.defineProperty(exports, "__esModule", { value: true });
 //// [b.js]
 "use strict";
 function default_1() { }
+Object.defineProperty(exports, "__esModule", { value: true });
 exports.default = default_1;
diff --git a/tests/baselines/reference/anonymousDefaultExportsUmd.js b/tests/baselines/reference/anonymousDefaultExportsUmd.js
index bdaf8dc6aa802..bea0c6d423890 100644
--- a/tests/baselines/reference/anonymousDefaultExportsUmd.js
+++ b/tests/baselines/reference/anonymousDefaultExportsUmd.js
@@ -19,6 +19,7 @@ export default function() {}
     class default_1 {
     }
     exports.default = default_1;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 (function (factory) {
@@ -31,5 +32,6 @@ export default function() {}
 })(function (require, exports) {
     "use strict";
     function default_1() { }
+    Object.defineProperty(exports, "__esModule", { value: true });
     exports.default = default_1;
 });
diff --git a/tests/baselines/reference/decoratedDefaultExportsGetExportedAmd.js b/tests/baselines/reference/decoratedDefaultExportsGetExportedAmd.js
index 05323aa247dbe..274541a24269f 100644
--- a/tests/baselines/reference/decoratedDefaultExportsGetExportedAmd.js
+++ b/tests/baselines/reference/decoratedDefaultExportsGetExportedAmd.js
@@ -29,6 +29,7 @@ define(["require", "exports"], function (require, exports) {
         decorator
     ], Foo);
     exports.default = Foo;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
@@ -46,4 +47,5 @@ define(["require", "exports"], function (require, exports) {
         decorator
     ], default_1);
     exports.default = default_1;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
diff --git a/tests/baselines/reference/decoratedDefaultExportsGetExportedCommonjs.js b/tests/baselines/reference/decoratedDefaultExportsGetExportedCommonjs.js
index 32e053789ce83..da62f648067da 100644
--- a/tests/baselines/reference/decoratedDefaultExportsGetExportedCommonjs.js
+++ b/tests/baselines/reference/decoratedDefaultExportsGetExportedCommonjs.js
@@ -28,6 +28,7 @@ Foo = __decorate([
     decorator
 ], Foo);
 exports.default = Foo;
+Object.defineProperty(exports, "__esModule", { value: true });
 //// [b.js]
 "use strict";
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
@@ -43,3 +44,4 @@ default_1 = __decorate([
     decorator
 ], default_1);
 exports.default = default_1;
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/decoratedDefaultExportsGetExportedUmd.js b/tests/baselines/reference/decoratedDefaultExportsGetExportedUmd.js
index d65bc33575b72..7598ee9a79777 100644
--- a/tests/baselines/reference/decoratedDefaultExportsGetExportedUmd.js
+++ b/tests/baselines/reference/decoratedDefaultExportsGetExportedUmd.js
@@ -36,6 +36,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
         decorator
     ], Foo);
     exports.default = Foo;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
@@ -60,4 +61,5 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
         decorator
     ], default_1);
     exports.default = default_1;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
diff --git a/tests/baselines/reference/defaultExportsGetExportedAmd.js b/tests/baselines/reference/defaultExportsGetExportedAmd.js
index fd9927250cbcd..13c169495e9fe 100644
--- a/tests/baselines/reference/defaultExportsGetExportedAmd.js
+++ b/tests/baselines/reference/defaultExportsGetExportedAmd.js
@@ -13,10 +13,12 @@ define(["require", "exports"], function (require, exports) {
     class Foo {
     }
     exports.default = Foo;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 define(["require", "exports"], function (require, exports) {
     "use strict";
     function foo() { }
+    Object.defineProperty(exports, "__esModule", { value: true });
     exports.default = foo;
 });
diff --git a/tests/baselines/reference/defaultExportsGetExportedCommonjs.js b/tests/baselines/reference/defaultExportsGetExportedCommonjs.js
index 8b97cff5d3894..311bffcd1ecf7 100644
--- a/tests/baselines/reference/defaultExportsGetExportedCommonjs.js
+++ b/tests/baselines/reference/defaultExportsGetExportedCommonjs.js
@@ -12,7 +12,9 @@ export default function foo() {}
 class Foo {
 }
 exports.default = Foo;
+Object.defineProperty(exports, "__esModule", { value: true });
 //// [b.js]
 "use strict";
 function foo() { }
+Object.defineProperty(exports, "__esModule", { value: true });
 exports.default = foo;
diff --git a/tests/baselines/reference/defaultExportsGetExportedUmd.js b/tests/baselines/reference/defaultExportsGetExportedUmd.js
index 2d442e42061a5..48fe5d3107676 100644
--- a/tests/baselines/reference/defaultExportsGetExportedUmd.js
+++ b/tests/baselines/reference/defaultExportsGetExportedUmd.js
@@ -20,6 +20,7 @@ export default function foo() {}
     class Foo {
     }
     exports.default = Foo;
+    Object.defineProperty(exports, "__esModule", { value: true });
 });
 //// [b.js]
 (function (factory) {
@@ -32,5 +33,6 @@ export default function foo() {}
 })(function (require, exports) {
     "use strict";
     function foo() { }
+    Object.defineProperty(exports, "__esModule", { value: true });
     exports.default = foo;
 });
diff --git a/tests/baselines/reference/es6ImportDefaultBindingFollowedWithNamedImport.js b/tests/baselines/reference/es6ImportDefaultBindingFollowedWithNamedImport.js
index 51fc7bf68970b..d7dfe29208d0d 100644
--- a/tests/baselines/reference/es6ImportDefaultBindingFollowedWithNamedImport.js
+++ b/tests/baselines/reference/es6ImportDefaultBindingFollowedWithNamedImport.js
@@ -27,6 +27,7 @@ var x1: number = m;
 exports.a = 10;
 exports.x = exports.a;
 exports.m = exports.a;
+Object.defineProperty(exports, "__esModule", { value: true });
 exports.default = {};
 //// [es6ImportDefaultBindingFollowedWithNamedImport_1.js]
 "use strict";
diff --git a/tests/baselines/reference/esModuleEmitForDefaultExport.js b/tests/baselines/reference/esModuleEmitForDefaultExport.js
new file mode 100644
index 0000000000000..e2ef4402ee0e5
--- /dev/null
+++ b/tests/baselines/reference/esModuleEmitForDefaultExport.js
@@ -0,0 +1,32 @@
+//// [tests/cases/compiler/esModuleEmitForDefaultExport.ts] ////
+
+//// [a.ts]
+
+class C { }
+export default C;
+
+//// [b.ts]
+var x = 0;
+export default x;
+
+//// [c.ts]
+function f() { }
+export default f;
+
+
+//// [a.js]
+"use strict";
+class C {
+}
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = C;
+//// [b.js]
+"use strict";
+var x = 0;
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = x;
+//// [c.js]
+"use strict";
+function f() { }
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = f;
diff --git a/tests/baselines/reference/esModuleEmitForDefaultExport.symbols b/tests/baselines/reference/esModuleEmitForDefaultExport.symbols
new file mode 100644
index 0000000000000..986bbd51ead93
--- /dev/null
+++ b/tests/baselines/reference/esModuleEmitForDefaultExport.symbols
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/a.ts ===
+
+class C { }
+>C : Symbol(C, Decl(a.ts, 0, 0))
+
+export default C;
+>C : Symbol(C, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.ts ===
+var x = 0;
+>x : Symbol(x, Decl(b.ts, 0, 3))
+
+export default x;
+>x : Symbol(x, Decl(b.ts, 0, 3))
+
+=== tests/cases/compiler/c.ts ===
+function f() { }
+>f : Symbol(f, Decl(c.ts, 0, 0))
+
+export default f;
+>f : Symbol(f, Decl(c.ts, 0, 0))
+
diff --git a/tests/baselines/reference/esModuleEmitForDefaultExport.types b/tests/baselines/reference/esModuleEmitForDefaultExport.types
new file mode 100644
index 0000000000000..36670913dc790
--- /dev/null
+++ b/tests/baselines/reference/esModuleEmitForDefaultExport.types
@@ -0,0 +1,23 @@
+=== tests/cases/compiler/a.ts ===
+
+class C { }
+>C : C
+
+export default C;
+>C : C
+
+=== tests/cases/compiler/b.ts ===
+var x = 0;
+>x : number
+>0 : number
+
+export default x;
+>x : number
+
+=== tests/cases/compiler/c.ts ===
+function f() { }
+>f : () => void
+
+export default f;
+>f : () => void
+
diff --git a/tests/baselines/reference/exportsAndImports4-es6.js b/tests/baselines/reference/exportsAndImports4-es6.js
index 3d3278b4462a8..39c6583e9359f 100644
--- a/tests/baselines/reference/exportsAndImports4-es6.js
+++ b/tests/baselines/reference/exportsAndImports4-es6.js
@@ -41,6 +41,7 @@ export { a, b, c, d, e1, e2, f1, f2 };
 
 //// [t1.js]
 "use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
 exports.default = "hello";
 //// [t3.js]
 "use strict";
diff --git a/tests/baselines/reference/outFilerootDirModuleNamesAmd.js b/tests/baselines/reference/outFilerootDirModuleNamesAmd.js
index 66d280839d407..881c41b60f0e2 100644
--- a/tests/baselines/reference/outFilerootDirModuleNamesAmd.js
+++ b/tests/baselines/reference/outFilerootDirModuleNamesAmd.js
@@ -14,6 +14,7 @@ export default function foo() { new Foo(); }
 define("b", ["require", "exports", "a"], function (require, exports, a_1) {
     "use strict";
     function foo() { new a_1.default(); }
+    Object.defineProperty(exports, "__esModule", { value: true });
     exports.default = foo;
 });
 define("a", ["require", "exports", "b"], function (require, exports, b_1) {
@@ -21,5 +22,6 @@ define("a", ["require", "exports", "b"], function (require, exports, b_1) {
     class Foo {
     }
     exports.default = Foo;
+    Object.defineProperty(exports, "__esModule", { value: true });
     b_1.default();
 });
diff --git a/tests/cases/compiler/esModuleEmitForDefaultExport.ts b/tests/cases/compiler/esModuleEmitForDefaultExport.ts
new file mode 100644
index 0000000000000..12f9ae1129c68
--- /dev/null
+++ b/tests/cases/compiler/esModuleEmitForDefaultExport.ts
@@ -0,0 +1,14 @@
+// @target: ES6
+// @module: commonjs
+
+// @filename: a.ts
+class C { }
+export default C;
+
+// @filename: b.ts
+var x = 0;
+export default x;
+
+// @filename: c.ts
+function f() { }
+export default f;