diff --git a/src/lib/es2015.collection.d.ts b/src/lib/es2015.collection.d.ts
index bde1c6d581123..6a2c43cd050f7 100644
--- a/src/lib/es2015.collection.d.ts
+++ b/src/lib/es2015.collection.d.ts
@@ -1,7 +1,7 @@
 interface Map<K, V> {
     clear(): void;
     delete(key: K): boolean;
-    forEach(callbackfn: (value: V, index: K, map: Map<K, V>) => void, thisArg?: any): void;
+    forEach(callbackfn: (value: V, key: K, map: Map<K, V>) => void, thisArg?: any): void;
     get(key: K): V | undefined;
     has(key: K): boolean;
     set(key: K, value?: V): this;
@@ -15,6 +15,13 @@ interface MapConstructor {
 }
 declare var Map: MapConstructor;
 
+interface ReadonlyMap<K, V> {
+    forEach(callbackfn: (value: V, key: K, map: ReadonlyMap<K, V>) => void, thisArg?: any): void;
+    get(key: K): V|undefined;
+    has(key: K): boolean;
+    readonly size: number;
+}
+
 interface WeakMap<K, V> {
     delete(key: K): boolean;
     get(key: K): V | undefined;
@@ -33,7 +40,7 @@ interface Set<T> {
     add(value: T): this;
     clear(): void;
     delete(value: T): boolean;
-    forEach(callbackfn: (value: T, index: T, set: Set<T>) => void, thisArg?: any): void;
+    forEach(callbackfn: (value: T, value2: T, set: Set<T>) => void, thisArg?: any): void;
     has(value: T): boolean;
     readonly size: number;
 }
@@ -45,6 +52,12 @@ interface SetConstructor {
 }
 declare var Set: SetConstructor;
 
+interface ReadonlySet<T> {
+    forEach(callbackfn: (value: T, value2: T, set: ReadonlySet<T>) => void, thisArg?: any): void;
+    has(value: T): boolean;
+    readonly size: number;
+}
+
 interface WeakSet<T> {
     add(value: T): this;
     delete(value: T): boolean;