diff --git a/lib/lib.d.ts b/lib/lib.d.ts
index 25d5a28dc9c39..de8238ea5a90b 100644
--- a/lib/lib.d.ts
+++ b/lib/lib.d.ts
@@ -248,7 +248,7 @@ interface ObjectConstructor {
       * Returns the names of the enumerable properties and methods of an object.
       * @param o Object that contains the properties and methods. This can be an object that you created or an existing Document Object Model (DOM) object.
       */
-    keys(o: {}): string[];
+    keys<T>(o: T): (keyof T)[];
 }
 
 /**