diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 859eb0e77d7..479668ae618 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -945,7 +945,7 @@ interface RegExp {
 
     // Non-standard extensions
     /** @deprecated A legacy feature for browser compatibility */
-    compile(): this;
+    compile(pattern: string, flags?: string): this;
 }
 
 interface RegExpConstructor {