diff --git a/src/lib/es2015.symbol.d.ts b/src/lib/es2015.symbol.d.ts
index cd7e45595f0..d7ea4fa0328 100644
--- a/src/lib/es2015.symbol.d.ts
+++ b/src/lib/es2015.symbol.d.ts
@@ -3,7 +3,7 @@ interface Symbol {
     toString(): string;
 
     /** Returns the primitive value of the specified object. */
-    valueOf(): Object;
+    valueOf(): symbol;
 }
 
 interface SymbolConstructor {