diff --git a/lib/relation-definition.js b/lib/relation-definition.js
index 7b90c18b..b9c298f8 100644
--- a/lib/relation-definition.js
+++ b/lib/relation-definition.js
@@ -64,12 +64,15 @@ function extendScopeMethods(definition, scopeMethods, ext) {
   if (typeof ext === 'function') {
     customMethods = ext.call(definition, scopeMethods, relationClass);
   } else if (typeof ext === 'object') {
+    function createFunc(definition, relationMethod) {
+        return function() {
+          var relation = new relationClass(definition, this);
+          return relationMethod.apply(relation, arguments);
+        };
+    };
     for (var key in ext) {
       var relationMethod = ext[key];
-      var method = scopeMethods[key] = function () {
-        var relation = new relationClass(definition, this);
-        return relationMethod.apply(relation, arguments);
-      };
+      var method = scopeMethods[key] = createFunc(definition, relationMethod);
       if (relationMethod.shared) {
         sharedMethod(definition, key, method, relationMethod);
       }