Index: django/core/handlers/base.py
===================================================================
--- django/core/handlers/base.py	(revision 6976)
+++ django/core/handlers/base.py	(working copy)
@@ -90,8 +91,8 @@
                         return response
                 raise
 
-            # Complain if the view returned None (a common error).
-            if response is None:
+            # Complain if the view did not return a http.HttpResonse object.
+            if not isinstance(response, http.HttpResponse):
                 try:
                     view_name = callback.func_name # If it's a function
                 except AttributeError: