diff --git a/src/CollectionImpl.js b/src/CollectionImpl.js
index f030767b48..092e75ee2e 100644
--- a/src/CollectionImpl.js
+++ b/src/CollectionImpl.js
@@ -70,14 +70,7 @@ import { getIn } from './methods/getIn';
 import { hasIn } from './methods/hasIn';
 import { toObject } from './methods/toObject';
 
-export {
-  Collection,
-  KeyedCollection,
-  IndexedCollection,
-  SetCollection,
-  CollectionPrototype,
-  IndexedCollectionPrototype,
-};
+export { Collection, CollectionPrototype, IndexedCollectionPrototype };
 
 // Note: all of these methods are deprecated.
 Collection.isIterable = isCollection;
diff --git a/src/List.js b/src/List.js
index 5f37846732..7006e93bfc 100644
--- a/src/List.js
+++ b/src/List.js
@@ -236,7 +236,7 @@ export class List extends IndexedCollection {
 
 List.isList = isList;
 
-export const ListPrototype = List.prototype;
+const ListPrototype = List.prototype;
 ListPrototype[IS_LIST_SYMBOL] = true;
 ListPrototype[DELETE] = ListPrototype.remove;
 ListPrototype.merge = ListPrototype.concat;
diff --git a/src/Map.js b/src/Map.js
index 9a3628c691..7ae3dd750d 100644
--- a/src/Map.js
+++ b/src/Map.js
@@ -160,7 +160,7 @@ export class Map extends KeyedCollection {
 
 Map.isMap = isMap;
 
-export const MapPrototype = Map.prototype;
+const MapPrototype = Map.prototype;
 MapPrototype[IS_MAP_SYMBOL] = true;
 MapPrototype[DELETE] = MapPrototype.remove;
 MapPrototype.removeAll = MapPrototype.deleteAll;
diff --git a/src/utils/createClass.js b/src/utils/createClass.js
deleted file mode 100644
index d11f6e9793..0000000000
--- a/src/utils/createClass.js
+++ /dev/null
@@ -1,6 +0,0 @@
-export default function createClass(ctor, superClass) {
-  if (superClass) {
-    ctor.prototype = Object.create(superClass.prototype);
-  }
-  ctor.prototype.constructor = ctor;
-}