diff --git a/src/lib/es2015.symbol.wellknown.d.ts b/src/lib/es2015.symbol.wellknown.d.ts
index 89d7b82eae0..dce75ddab70 100644
--- a/src/lib/es2015.symbol.wellknown.d.ts
+++ b/src/lib/es2015.symbol.wellknown.d.ts
@@ -63,6 +63,11 @@ interface SymbolConstructor {
 }
 
 interface Symbol {
+    /**
+     * Converts a Symbol object to a symbol.
+     */
+    [Symbol.toPrimitive](hint: string): symbol;
+
     readonly [Symbol.toStringTag]: string;
 }
 
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 5df54f51fe0..807d056c665 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1692,6 +1692,7 @@ interface DataView {
 }
 
 interface DataViewConstructor {
+    readonly prototype: DataView;
     new(buffer: ArrayBufferLike, byteOffset?: number, byteLength?: number): DataView;
 }
 declare var DataView: DataViewConstructor;