diff --git a/lib/6to5/transformation/transformers/es6-classes.js b/lib/6to5/transformation/transformers/es6-classes.js
index ffa8f0e47f..0d39bdc565 100644
--- a/lib/6to5/transformation/transformers/es6-classes.js
+++ b/lib/6to5/transformation/transformers/es6-classes.js
@@ -58,15 +58,23 @@ Class.prototype.run = function () {
     t.variableDeclarator(className, constructor)
   ]));
 
+  var closureArgs = [];
+  var closureParams = [];
+
   //
 
   if (superName) {
-    // so we're only evaluating it once
-    var superRef = this.scope.generateUidBasedOnNode(superName, this.file);
-    body.unshift(t.variableDeclaration("var", [
-      t.variableDeclarator(superRef, superName)
-    ]));
-    superName = superRef;
+    closureArgs.push(superName);
+
+    if (!t.isIdentifier(superName)) {
+      var superRef = this.scope.generateUidBasedOnNode(superName, this.file);
+      body.unshift(t.variableDeclaration("var", [
+        t.variableDeclarator(superRef, superName)
+      ]));
+      superName = superRef;
+    }
+
+    closureParams.push(superName);
 
     this.superName = superName;
     body.push(t.expressionStatement(t.callExpression(file.addHelper("inherits"), [className, superName])));
@@ -84,8 +92,8 @@ Class.prototype.run = function () {
   } else {
     body.push(t.returnStatement(className));
     init = t.callExpression(
-      t.functionExpression(null, [], t.blockStatement(body)),
-      []
+      t.functionExpression(null, closureParams, t.blockStatement(body)),
+      closureArgs
     );
   }
 
@@ -212,25 +220,12 @@ Class.prototype.superProperty = function (property, isStatic, isComputed) {
     this.file.addHelper("get"),
     [
       t.callExpression(
-        t.memberExpression(
-          t.identifier("Object"),
-          t.identifier("getPrototypeOf"),
-          false
-        ),
+        t.memberExpression(t.identifier("Object"), t.identifier("getPrototypeOf")),
         [
-          isStatic ?
-            this.className :
-            t.memberExpression(
-              this.className,
-              t.identifier("prototype"),
-              false
-            )
+          isStatic ? this.className : t.memberExpression(this.className, t.identifier("prototype"))
         ]
       ),
-      isComputed ?
-        property :
-        t.literal(property.name),
-      t.thisExpression()
+      isComputed ? property : t.literal(property.name), t.thisExpression()
     ]
   );
 };
diff --git a/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js b/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js
index 67abcf3cb4..c556d7c015 100644
--- a/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js
+++ b/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js
@@ -38,8 +38,7 @@ var _inherits = function (child, parent) {
   if (parent) child.__proto__ = parent;
 };
 
-var Test = (function () {
-  var _Foo = Foo;
+var Test = (function (Foo) {
   var Test = function Test() {
     var _get2, _get3, _get4, _get5;
     woops["super"].test();
@@ -53,7 +52,7 @@ var Test = (function () {
     (_get5 = _get(Object.getPrototypeOf(Test.prototype), "test", this)).call.apply(_get5, [this, "test"].concat(_slice.call(arguments)));
   };
 
-  _inherits(Test, _Foo);
+  _inherits(Test, Foo);
 
   Test.prototype.test = function () {
     var _get6, _get7;
@@ -70,5 +69,4 @@ var Test = (function () {
   };
 
   return Test;
-})();
-
+})(Foo);
diff --git a/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js b/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js
index 5c06e689e1..fe231fa303 100644
--- a/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js
+++ b/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js
@@ -37,15 +37,13 @@ var _inherits = function (child, parent) {
   if (parent) child.__proto__ = parent;
 };
 
-var Test = (function () {
-  var _Foo = Foo;
+var Test = (function (Foo) {
   var Test = function Test() {
     _get(Object.getPrototypeOf(Test.prototype), "test", this);
     _get(Object.getPrototypeOf(Test.prototype), "test", this).whatever;
   };
 
-  _inherits(Test, _Foo);
+  _inherits(Test, Foo);
 
   return Test;
-})();
-
+})(Foo);
diff --git a/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js b/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js
index 24595cd8ba..ce7a061321 100644
--- a/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js
+++ b/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js
@@ -37,19 +37,17 @@ var _inherits = function (child, parent) {
   if (parent) child.__proto__ = parent;
 };
 
-var Test = (function () {
-  var _Foo = Foo;
+var Test = (function (Foo) {
   var Test = function Test() {
     _get(Object.getPrototypeOf(Test.prototype), "test", this).whatever();
     _get(Object.getPrototypeOf(Test.prototype), "test", this).call(this);
   };
 
-  _inherits(Test, _Foo);
+  _inherits(Test, Foo);
 
   Test.test = function () {
     return _get(Object.getPrototypeOf(Test), "wow", this).call(this);
   };
 
   return Test;
-})();
-
+})(Foo);
diff --git a/test/fixtures/transformation/es6-classes/constructor/expected.js b/test/fixtures/transformation/es6-classes/constructor/expected.js
index cc5264d5b6..ce1a7be09c 100644
--- a/test/fixtures/transformation/es6-classes/constructor/expected.js
+++ b/test/fixtures/transformation/es6-classes/constructor/expected.js
@@ -19,13 +19,12 @@ var Test = function Test() {
   this.state = "test";
 };
 
-var Foo = (function () {
-  var _Bar = Bar;
+var Foo = (function (Bar) {
   var Foo = function Foo() {
     this.state = "test";
   };
 
-  _inherits(Foo, _Bar);
+  _inherits(Foo, Bar);
 
   return Foo;
-})();
+})(Bar);
diff --git a/test/fixtures/transformation/es6-classes/super-class-id-member-expression/expected.js b/test/fixtures/transformation/es6-classes/super-class-id-member-expression/expected.js
index a8ecac411b..929f727aed 100644
--- a/test/fixtures/transformation/es6-classes/super-class-id-member-expression/expected.js
+++ b/test/fixtures/transformation/es6-classes/super-class-id-member-expression/expected.js
@@ -15,7 +15,7 @@ var _inherits = function (child, parent) {
   if (parent) child.__proto__ = parent;
 };
 
-var BaseController = (function () {
+var BaseController = (function (_Chaplin$Controller) {
   var _Chaplin$Controller = Chaplin.Controller;
   var BaseController = function BaseController() {
     if (Object.getPrototypeOf(BaseController) !== null) {
@@ -26,9 +26,9 @@ var BaseController = (function () {
   _inherits(BaseController, _Chaplin$Controller);
 
   return BaseController;
-})();
+})(Chaplin.Controller);
 
-var BaseController2 = (function () {
+var BaseController2 = (function (_Chaplin$Controller$Another) {
   var _Chaplin$Controller$Another = Chaplin.Controller.Another;
   var BaseController2 = function BaseController2() {
     if (Object.getPrototypeOf(BaseController2) !== null) {
@@ -39,4 +39,4 @@ var BaseController2 = (function () {
   _inherits(BaseController2, _Chaplin$Controller$Another);
 
   return BaseController2;
-})();
+})(Chaplin.Controller.Another);
diff --git a/test/fixtures/transformation/es6-classes/super-class/expected.js b/test/fixtures/transformation/es6-classes/super-class/expected.js
index fdd356cf96..bd9234406b 100644
--- a/test/fixtures/transformation/es6-classes/super-class/expected.js
+++ b/test/fixtures/transformation/es6-classes/super-class/expected.js
@@ -15,15 +15,14 @@ var _inherits = function (child, parent) {
   if (parent) child.__proto__ = parent;
 };
 
-var Test = (function () {
-  var _Foo = Foo;
+var Test = (function (Foo) {
   var Test = function Test() {
     if (Object.getPrototypeOf(Test) !== null) {
       Object.getPrototypeOf(Test).apply(this, arguments);
     }
   };
 
-  _inherits(Test, _Foo);
+  _inherits(Test, Foo);
 
   return Test;
-})();
+})(Foo);
diff --git a/test/fixtures/transformation/optional-proto-to-assign/class/expected.js b/test/fixtures/transformation/optional-proto-to-assign/class/expected.js
index b6517c4263..59892c84f0 100644
--- a/test/fixtures/transformation/optional-proto-to-assign/class/expected.js
+++ b/test/fixtures/transformation/optional-proto-to-assign/class/expected.js
@@ -25,15 +25,14 @@ var _inherits = function (child, parent) {
   if (parent) _defaults(child, parent);
 };
 
-var Foo = (function () {
-  var _Bar = Bar;
+var Foo = (function (Bar) {
   var Foo = function Foo() {
     if (Object.getPrototypeOf(Foo) !== null) {
       Object.getPrototypeOf(Foo).apply(this, arguments);
     }
   };
 
-  _inherits(Foo, _Bar);
+  _inherits(Foo, Bar);
 
   return Foo;
-})();
+})(Bar);