diff --git a/inversify/inversify-tests.ts b/inversify/inversify-tests.ts
index c69bd064e..8d2d99d5c 100644
--- a/inversify/inversify-tests.ts
+++ b/inversify/inversify-tests.ts
@@ -19,7 +19,7 @@ module external_module_test {
     }
 
     interface IShuriken {
-        throw();
+        throw(): string;
     }
 
     class Katana implements IKatana {