diff --git a/es-collections.d.ts b/es-collections.d.ts
new file mode 100644
index 000000000..ab3315843
--- /dev/null
+++ b/es-collections.d.ts
@@ -0,0 +1,40 @@
+/////////////////////////////
+/// IE11 ECMAScript Extensions
+/////////////////////////////
+
+interface Map<K, V> {
+    clear(): void;
+    delete(key: K): boolean;
+    forEach(callbackfn: (value: V, index: K, map: Map<K, V>) => void, thisArg?: any): void;
+    get(key: K): V;
+    has(key: K): boolean;
+    set(key: K, value: V): Map<K, V>;
+    size: number;
+}
+declare var Map: {
+    new <K, V>(): Map<K, V>;
+
+    // needed by Angular
+    // alexeagle: PATCHED
+    new<K, V>(m: Map<K, V>): Map<K, V>;
+    new<K, V>(l: List<any>): Map<K, V>;
+    prototype: Map<any, any>;
+}
+
+interface Set<T> {
+    add(value: T): Set<T>;
+    clear(): void;
+    delete(value: T): boolean;
+    forEach(callbackfn: (value: T, index: T, set: Set<T>) => void, thisArg?: any): void;
+    has(value: T): boolean;
+    size: number;
+}
+declare var Set: {
+    new <T>(): Set<T>;
+
+    // needed by Angular
+    // alexeagle PATCHED
+    new<T>(s: Set<T>): Set<T>;
+    new<T>(l: List<T>): Set<T>;
+    prototype: Set<any>;
+}
diff --git a/libjs.d.ts b/libjs.d.ts
index a31a103a7..acb290089 100644
--- a/libjs.d.ts
+++ b/libjs.d.ts
@@ -1756,23 +1756,6 @@ declare var DataView: {
     new (buffer: ArrayBuffer, byteOffset?: number, length?: number): DataView;
 }
 
-/////////////////////////////
-/// IE11 ECMAScript Extensions
-/////////////////////////////
-
-interface Map<K, V> {
-    clear(): void;
-    delete(key: K): boolean;
-    forEach(callbackfn: (value: V, index: K, map: Map<K, V>) => void, thisArg?: any): void;
-    get(key: K): V;
-    has(key: K): boolean;
-    set(key: K, value: V): Map<K, V>;
-    size: number;
-}
-declare var Map: {
-    new <K, V>(): Map<K, V>;
-}
-
 interface WeakMap<K, V> {
     clear(): void;
     delete(key: K): boolean;
@@ -1784,15 +1767,4 @@ declare var WeakMap: {
     new <K, V>(): WeakMap<K, V>;
 }
 
-interface Set<T> {
-    add(value: T): Set<T>;
-    clear(): void;
-    delete(value: T): boolean;
-    forEach(callbackfn: (value: T, index: T, set: Set<T>) => void, thisArg?: any): void;
-    has(value: T): boolean;
-    size: number;
-}
-declare var Set: {
-    new <T>(): Set<T>;
-}
- 
\ No newline at end of file
+declare function alert(message: string): Promise<void>;