diff --git a/lib/specs/spec_0_3.js b/lib/specs/spec_0_3.js
index 13256f2..0a778b6 100644
--- a/lib/specs/spec_0_3.js
+++ b/lib/specs/spec_0_3.js
@@ -36,6 +36,10 @@ function Spec03(_caller){
     id: uuid()
   };
 
+  if(!_caller){
+    _caller = require("../cloudevent.js");
+  }
+
   /*
    * Used to inject compatibility methods or attributes
    */