diff --git a/backbone.js b/backbone.js
index 69ce1168d..6ebc6c901 100644
--- a/backbone.js
+++ b/backbone.js
@@ -1133,7 +1133,7 @@
     child.prototype.constructor = child;
 
     // Set a convenience property in case the parent's prototype is needed later.
-    child.__super__ = parent.prototype;
+    child.prototype.__super__ = parent.prototype;
 
     return child;
   };