diff --git a/test/com/google/javascript/jscomp/IntegrationTestCase.java b/test/com/google/javascript/jscomp/IntegrationTestCase.java
index 148e08b2369..a83b78400b8 100644
--- a/test/com/google/javascript/jscomp/IntegrationTestCase.java
+++ b/test/com/google/javascript/jscomp/IntegrationTestCase.java
@@ -35,116 +35,120 @@ abstract class IntegrationTestCase extends TestCase {
   protected static final Joiner LINE_JOINER = Joiner.on('\n');
 
   /** Externs for the test */
-  protected static final List<SourceFile> DEFAULT_EXTERNS =
-      ImmutableList.of(SourceFile.fromCode("externs", LINE_JOINER.join(
-          "var arguments;",
-          "var undefined;",
-          "var Math;",
-          "var isNaN;",
-          "var Infinity;",
-          "/** @interface */",
-          "var Iterator = function() {};",
-          "/** @interface */",
-          "var Iterable = function() {};",
-          "/** @interface @extends {Iterator} @extends {Iterable} */",
-          "var IteratorIterable = function() {};",
-          "/** @interface */",
-          "function IArrayLike() {};",
-          // TODO(sdh): See if we can remove IIterableResult and Set once polyfills are split
-          "/** @interface */",
-          "var IIterableResult = function() {};",
-          "/** @constructor */",
-          "var Map;",
-          "/** @constructor */",
-          "var Set;",
-          "/** @constructor */",
-          "function ObjectPropertyDescriptor() {};",
-          "",
-          "/** @constructor */ function Window() {}",
-          "/** @type {string} */ Window.prototype.name;",
-          "/** @type {string} */ Window.prototype.offsetWidth;",
-          "/** @type {Window} */ var window;",
-          "",
-          "/** @nosideeffects */ function noSideEffects() {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @nosideeffects",
-          " */",
-          "function Widget() {}",
-          "/** @modifies {this} */ Widget.prototype.go = function() {};",
-          "/** @return {string} */ var widgetToken = function() {};",
-          "",
-          "function alert(message) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @implements {IArrayLike}",
-          " * @return {!Array}",
-          " * @param {...*} var_args",
-          " */",
-          "function Array(var_args) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @return {number}",
-          " * @param {*=} opt_n",
-          " */",
-          "function Number(opt_n) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @return {string}",
-          " * @param {*=} opt_s",
-          " */",
-          "function String(opt_s) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @return {boolean}",
-          " * @param {*=} opt_b",
-          " */",
-          "function Boolean(opt_b) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @return {!TypeError}",
-          " * @param {*=} opt_message",
-          " * @param {*=} opt_file",
-          " * @param {*=} opt_line",
-          " */",
-          "function TypeError(opt_message, opt_file, opt_line) {}",
-          "",
-          "/**",
-          " * @constructor",
-          " * @param {*=} opt_value",
-          " * @return {!Object}",
-          " */",
-          "function Object(opt_value) {}",
-          "Object.seal;",
-          "Object.defineProperties;",
-          "/** @type {!Function} */",
-          "Object.prototype.constructor;",
-          "",
-          "/** @typedef {?} */",
-          "var symbol;",
-          "",
-          "/**",
-          " * @param {string} s",
-          " * @return {symbol}",
-          " */",
-          "function Symbol(s) {}",
-          "",
-          "/**",
-          " * @param {...*} var_args",
-          " * @constructor",
-          " */",
-          "function Function(var_args) {}",
-          "/** @param {...*} var_args */",
-          "Function.prototype.call = function (var_args) {};",
-          "",
-          "/** @constructor */",
-          "function Arguments() {}")));
+  protected static final ImmutableList<SourceFile> DEFAULT_EXTERNS =
+      ImmutableList.of(
+          SourceFile.fromCode(
+              "externs",
+              LINE_JOINER.join(
+                  "var arguments;",
+                  "var undefined;",
+                  "var Math;",
+                  "var isNaN;",
+                  "var Infinity;",
+                  "/** @interface */",
+                  "var Iterator = function() {};",
+                  "/** @interface */",
+                  "var Iterable = function() {};",
+                  "/** @interface @extends {Iterator} @extends {Iterable} */",
+                  "var IteratorIterable = function() {};",
+                  "/** @interface */",
+                  "function IArrayLike() {};",
+                  // TODO(sdh): See if we can remove IIterableResult and Set once polyfills are
+                  // split
+                  "/** @interface */",
+                  "var IIterableResult = function() {};",
+                  "/** @constructor */",
+                  "var Map;",
+                  "/** @constructor */",
+                  "var Set;",
+                  "/** @constructor */",
+                  "function ObjectPropertyDescriptor() {};",
+                  "",
+                  "/** @constructor */ function Window() {}",
+                  "/** @type {string} */ Window.prototype.name;",
+                  "/** @type {string} */ Window.prototype.offsetWidth;",
+                  "/** @type {Window} */ var window;",
+                  "",
+                  "/** @nosideeffects */ function noSideEffects() {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @nosideeffects",
+                  " */",
+                  "function Widget() {}",
+                  "/** @modifies {this} */ Widget.prototype.go = function() {};",
+                  "/** @return {string} */ var widgetToken = function() {};",
+                  "",
+                  "function alert(message) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @implements {IArrayLike}",
+                  " * @return {!Array}",
+                  " * @param {...*} var_args",
+                  " */",
+                  "function Array(var_args) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @return {number}",
+                  " * @param {*=} opt_n",
+                  " */",
+                  "function Number(opt_n) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @return {string}",
+                  " * @param {*=} opt_s",
+                  " */",
+                  "function String(opt_s) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @return {boolean}",
+                  " * @param {*=} opt_b",
+                  " */",
+                  "function Boolean(opt_b) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @return {!TypeError}",
+                  " * @param {*=} opt_message",
+                  " * @param {*=} opt_file",
+                  " * @param {*=} opt_line",
+                  " */",
+                  "function TypeError(opt_message, opt_file, opt_line) {}",
+                  "",
+                  "/**",
+                  " * @constructor",
+                  " * @param {*=} opt_value",
+                  " * @return {!Object}",
+                  " */",
+                  "function Object(opt_value) {}",
+                  "Object.seal;",
+                  "Object.defineProperties;",
+                  "/** @type {!Function} */",
+                  "Object.prototype.constructor;",
+                  "",
+                  "/** @typedef {?} */",
+                  "var symbol;",
+                  "",
+                  "/**",
+                  " * @param {string} s",
+                  " * @return {symbol}",
+                  " */",
+                  "function Symbol(s) {}",
+                  "",
+                  "/**",
+                  " * @param {...*} var_args",
+                  " * @constructor",
+                  " */",
+                  "function Function(var_args) {}",
+                  "/** @param {...*} var_args */",
+                  "Function.prototype.call = function (var_args) {};",
+                  "",
+                  "/** @constructor */",
+                  "function Arguments() {}")));
 
   protected List<SourceFile> externs = DEFAULT_EXTERNS;
 
diff --git a/test/com/google/javascript/jscomp/PeepholeFoldConstantsTest.java b/test/com/google/javascript/jscomp/PeepholeFoldConstantsTest.java
index 07e3ec767b5..e9f005bbedd 100644
--- a/test/com/google/javascript/jscomp/PeepholeFoldConstantsTest.java
+++ b/test/com/google/javascript/jscomp/PeepholeFoldConstantsTest.java
@@ -1330,7 +1330,7 @@ public void foldDefineProperties1() {
     testSame("Object.defineProperties(a, {anything:1})");
   }
 
-  private static final List<String> LITERAL_OPERANDS =
+  private static final ImmutableList<String> LITERAL_OPERANDS =
       ImmutableList.of(
           "null",
           "undefined",