diff --git a/extend/extend.d.ts b/extend/extend.d.ts
index 39b5d1a04c..b73ccc00de 100644
--- a/extend/extend.d.ts
+++ b/extend/extend.d.ts
@@ -5,5 +5,6 @@
 declare module "extend" {
 
     function extend(deepOrObject:boolean | Object, ...objectN: Object[]): any;
+    namespace extend {}
     export = extend;
-}
\ No newline at end of file
+}