diff --git a/lib/6to5/transformation/templates/inherits.js b/lib/6to5/transformation/templates/inherits.js
index 8822bbea7e..5596366744 100644
--- a/lib/6to5/transformation/templates/inherits.js
+++ b/lib/6to5/transformation/templates/inherits.js
@@ -1,14 +1,14 @@
-(function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+(function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 })
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 ba500fb940..883043cefa 100644
--- a/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js
+++ b/test/fixtures/transformation/es6-classes/accessing-super-class/expected.js
@@ -28,19 +28,19 @@ var _get = function get(object, property, receiver) {
   }
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (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 fe231fa303..52e3b4be2d 100644
--- a/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js
+++ b/test/fixtures/transformation/es6-classes/accessing-super-properties/expected.js
@@ -22,19 +22,19 @@ var _get = function get(object, property, receiver) {
   }
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (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 b388800218..d78dea51a6 100644
--- a/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js
+++ b/test/fixtures/transformation/es6-classes/calling-super-properties/expected.js
@@ -27,19 +27,19 @@ var _get = function get(object, property, receiver) {
   }
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (Foo) {
diff --git a/test/fixtures/transformation/es6-classes/constructor/expected.js b/test/fixtures/transformation/es6-classes/constructor/expected.js
index ce1a7be09c..ae8840986d 100644
--- a/test/fixtures/transformation/es6-classes/constructor/expected.js
+++ b/test/fixtures/transformation/es6-classes/constructor/expected.js
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = function Test() {
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 6e5d8fd829..08405597c2 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
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var BaseController = (function (_Chaplin$Controller) {
diff --git a/test/fixtures/transformation/es6-classes/super-class/expected.js b/test/fixtures/transformation/es6-classes/super-class/expected.js
index bd9234406b..c425a6db4b 100644
--- a/test/fixtures/transformation/es6-classes/super-class/expected.js
+++ b/test/fixtures/transformation/es6-classes/super-class/expected.js
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (Foo) {
diff --git a/test/fixtures/transformation/optional-classes-fast-super/accessing-super-class/expected.js b/test/fixtures/transformation/optional-classes-fast-super/accessing-super-class/expected.js
index 821e2b4f02..a66637e0eb 100644
--- a/test/fixtures/transformation/optional-classes-fast-super/accessing-super-class/expected.js
+++ b/test/fixtures/transformation/optional-classes-fast-super/accessing-super-class/expected.js
@@ -6,19 +6,19 @@ var _prototypeProperties = function (child, staticProps, instanceProps) {
   if (instanceProps) Object.defineProperties(child.prototype, instanceProps);
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (Foo) {
diff --git a/test/fixtures/transformation/optional-classes-fast-super/accessing-super-properties/expected.js b/test/fixtures/transformation/optional-classes-fast-super/accessing-super-properties/expected.js
index bf1a718a95..b6032c2891 100644
--- a/test/fixtures/transformation/optional-classes-fast-super/accessing-super-properties/expected.js
+++ b/test/fixtures/transformation/optional-classes-fast-super/accessing-super-properties/expected.js
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (Foo) {
diff --git a/test/fixtures/transformation/optional-classes-fast-super/calling-super-properties/expected.js b/test/fixtures/transformation/optional-classes-fast-super/calling-super-properties/expected.js
index 8eebc5204e..f1ec1f6da5 100644
--- a/test/fixtures/transformation/optional-classes-fast-super/calling-super-properties/expected.js
+++ b/test/fixtures/transformation/optional-classes-fast-super/calling-super-properties/expected.js
@@ -5,19 +5,19 @@ var _prototypeProperties = function (child, staticProps, instanceProps) {
   if (instanceProps) Object.defineProperties(child.prototype, instanceProps);
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (Foo) {
diff --git a/test/fixtures/transformation/optional-classes-fast-super/super-class-id-member-expression/expected.js b/test/fixtures/transformation/optional-classes-fast-super/super-class-id-member-expression/expected.js
index 058b2d7217..813528f129 100644
--- a/test/fixtures/transformation/optional-classes-fast-super/super-class-id-member-expression/expected.js
+++ b/test/fixtures/transformation/optional-classes-fast-super/super-class-id-member-expression/expected.js
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var BaseController = (function (_Chaplin$Controller) {
diff --git a/test/fixtures/transformation/optional-classes-fast-super/super-class/expected.js b/test/fixtures/transformation/optional-classes-fast-super/super-class/expected.js
index 4628b9a5ef..1725f9b1bf 100644
--- a/test/fixtures/transformation/optional-classes-fast-super/super-class/expected.js
+++ b/test/fixtures/transformation/optional-classes-fast-super/super-class/expected.js
@@ -1,18 +1,18 @@
 "use strict";
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) child.__proto__ = parent;
+  if (superClass) subClass.__proto__ = superClass;
 };
 
 var Test = (function (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 59892c84f0..a4d0ea8aef 100644
--- a/test/fixtures/transformation/optional-proto-to-assign/class/expected.js
+++ b/test/fixtures/transformation/optional-proto-to-assign/class/expected.js
@@ -10,19 +10,19 @@ var _defaults = function (obj, defaults) {
   return obj;
 };
 
-var _inherits = function (child, parent) {
-  if (typeof parent !== "function" && parent !== null) {
-    throw new TypeError("Super expression must either be null or a function, not " + typeof parent);
+var _inherits = function (subClass, superClass) {
+  if (typeof superClass !== "function" && superClass !== null) {
+    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
   }
-  child.prototype = Object.create(parent && parent.prototype, {
+  subClass.prototype = Object.create(superClass && superClass.prototype, {
     constructor: {
-      value: child,
+      value: subClass,
       enumerable: false,
       writable: true,
       configurable: true
     }
   });
-  if (parent) _defaults(child, parent);
+  if (superClass) _defaults(subClass, superClass);
 };
 
 var Foo = (function (Bar) {