diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 9670b44d80e..1665da1431f 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -478,7 +478,7 @@ module ts {
             return "__" + indexOf((<SignatureDeclaration>node.parent).parameters, node);
         }
 
-        function bind(node: Node) {
+        function bind(node: Node): void {
             node.parent = parent;
             
             switch (node.kind) {