diff --git a/src/lib/es2015.collection.d.ts b/src/lib/es2015.collection.d.ts
index fd49ca1f25b8a..46bb7af0c8fc7 100644
--- a/src/lib/es2015.collection.d.ts
+++ b/src/lib/es2015.collection.d.ts
@@ -9,8 +9,7 @@ interface Map<K, V> {
 }
 
 interface MapConstructor {
-    new (): Map<any, any>;
-    new <K, V>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
+    new <K = any, V = any>(entries?: ReadonlyArray<[K, V]> | null): Map<K, V>;
     readonly prototype: Map<any, any>;
 }
 declare var Map: MapConstructor;
@@ -45,8 +44,7 @@ interface Set<T> {
 }
 
 interface SetConstructor {
-    new (): Set<any>;
-    new <T>(values?: ReadonlyArray<T> | null): Set<T>;
+    new <T = any>(values?: ReadonlyArray<T> | null): Set<T>;
     readonly prototype: Set<any>;
 }
 declare var Set: SetConstructor;
@@ -64,8 +62,7 @@ interface WeakSet<T extends object> {
 }
 
 interface WeakSetConstructor {
-    new (): WeakSet<object>;
-    new <T extends object>(values?: ReadonlyArray<T> | null): WeakSet<T>;
+    new <T extends object = object>(values?: ReadonlyArray<T> | null): WeakSet<T>;
     readonly prototype: WeakSet<object>;
 }
 declare var WeakSet: WeakSetConstructor;
diff --git a/src/lib/es2015.iterable.d.ts b/src/lib/es2015.iterable.d.ts
index b7c04c60ce039..568d3596ddae3 100644
--- a/src/lib/es2015.iterable.d.ts
+++ b/src/lib/es2015.iterable.d.ts
@@ -135,7 +135,7 @@ interface MapConstructor {
 interface WeakMap<K extends object, V> { }
 
 interface WeakMapConstructor {
-    new <K extends object, V>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
+    new <K extends object = object, V = any>(iterable: Iterable<[K, V]>): WeakMap<K, V>;
 }
 
 interface Set<T> {
@@ -183,7 +183,7 @@ interface SetConstructor {
 interface WeakSet<T extends object> { }
 
 interface WeakSetConstructor {
-    new <T extends object>(iterable: Iterable<T>): WeakSet<T>;
+    new <T extends object = object>(iterable: Iterable<T>): WeakSet<T>;
 }
 
 interface Promise<T> { }
diff --git a/tests/baselines/reference/ES5For-ofTypeCheck13.types b/tests/baselines/reference/ES5For-ofTypeCheck13.types
index 4812ae8d82c4b..a1cdba4359b78 100644
--- a/tests/baselines/reference/ES5For-ofTypeCheck13.types
+++ b/tests/baselines/reference/ES5For-ofTypeCheck13.types
@@ -2,7 +2,7 @@
 const strSet: Set<string> = new Set()
 >strSet : Set<string>
 >Set : Set<T>
->new Set() : Set<any>
+>new Set() : Set<string>
 >Set : SetConstructor
 
 strSet.add('Hello')
diff --git a/tests/baselines/reference/extendingSetWithCheckJs.symbols b/tests/baselines/reference/extendingSetWithCheckJs.symbols
new file mode 100644
index 0000000000000..63bc853976373
--- /dev/null
+++ b/tests/baselines/reference/extendingSetWithCheckJs.symbols
@@ -0,0 +1,40 @@
+=== tests/cases/compiler/extendingSetWithCheckJs.ts ===
+class MySet extends Set {
+>MySet : Symbol(MySet, Decl(extendingSetWithCheckJs.ts, 0, 0))
+>Set : Symbol(Set, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+    constructor() {
+        super();
+>super : Symbol(SetConstructor, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+    }
+}
+
+class MyWeakSet extends WeakSet {
+>MyWeakSet : Symbol(MyWeakSet, Decl(extendingSetWithCheckJs.ts, 4, 1))
+>WeakSet : Symbol(WeakSet, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+    constructor() {
+        super();
+>super : Symbol(WeakSetConstructor, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --))
+    }
+}
+
+class MyMap extends Map {
+>MyMap : Symbol(MyMap, Decl(extendingSetWithCheckJs.ts, 10, 1))
+>Map : Symbol(Map, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+    constructor() {
+        super();
+>super : Symbol(MapConstructor, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+    }
+}
+
+class MyWeakMap extends WeakMap {
+>MyWeakMap : Symbol(MyWeakMap, Decl(extendingSetWithCheckJs.ts, 16, 1))
+>WeakMap : Symbol(WeakMap, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --))
+
+    constructor() {
+        super();
+>super : Symbol(WeakMapConstructor, Decl(lib.es2015.collection.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --))
+    }
+}
diff --git a/tests/baselines/reference/extendingSetWithCheckJs.types b/tests/baselines/reference/extendingSetWithCheckJs.types
new file mode 100644
index 0000000000000..dd10731e023ae
--- /dev/null
+++ b/tests/baselines/reference/extendingSetWithCheckJs.types
@@ -0,0 +1,44 @@
+=== tests/cases/compiler/extendingSetWithCheckJs.ts ===
+class MySet extends Set {
+>MySet : MySet
+>Set : Set<any>
+
+    constructor() {
+        super();
+>super() : void
+>super : SetConstructor
+    }
+}
+
+class MyWeakSet extends WeakSet {
+>MyWeakSet : MyWeakSet
+>WeakSet : WeakSet<object>
+
+    constructor() {
+        super();
+>super() : void
+>super : WeakSetConstructor
+    }
+}
+
+class MyMap extends Map {
+>MyMap : MyMap
+>Map : Map<any, any>
+
+    constructor() {
+        super();
+>super() : void
+>super : MapConstructor
+    }
+}
+
+class MyWeakMap extends WeakMap {
+>MyWeakMap : MyWeakMap
+>WeakMap : WeakMap<object, any>
+
+    constructor() {
+        super();
+>super() : void
+>super : WeakMapConstructor
+    }
+}
diff --git a/tests/cases/compiler/extendingSetWithCheckJs.ts b/tests/cases/compiler/extendingSetWithCheckJs.ts
new file mode 100644
index 0000000000000..b726a5e830c7f
--- /dev/null
+++ b/tests/cases/compiler/extendingSetWithCheckJs.ts
@@ -0,0 +1,28 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+// @lib: es2017
+
+class MySet extends Set {
+    constructor() {
+        super();
+    }
+}
+
+class MyWeakSet extends WeakSet {
+    constructor() {
+        super();
+    }
+}
+
+class MyMap extends Map {
+    constructor() {
+        super();
+    }
+}
+
+class MyWeakMap extends WeakMap {
+    constructor() {
+        super();
+    }
+}
\ No newline at end of file