diff --git a/django/core/handlers/base.py b/django/core/handlers/base.py
index 21737f682f..50495b4ff3 100644
--- a/django/core/handlers/base.py
+++ b/django/core/handlers/base.py
@@ -142,7 +142,7 @@ def fix_location_header(request, response):
     Code constructing response objects is free to insert relative paths and
     this function converts them to absolute paths.
     """
-    if 'location' in response.headers and http.get_host(request):
+    if 'Location' in response and http.get_host(request):
         response['Location'] = request.build_absolute_uri(response['Location'])
     return response
 
diff --git a/django/http/__init__.py b/django/http/__init__.py
index 1bb1621d77..e4aaf5a15f 100644
--- a/django/http/__init__.py
+++ b/django/http/__init__.py
@@ -273,6 +273,8 @@ class HttpResponse(object):
         "Case-insensitive check for a header"
 	return self.headers.has_key(header.lower())
 
+    __contains__ = has_header
+
     def set_cookie(self, key, value='', max_age=None, expires=None, path='/', domain=None, secure=None):
         self.cookies[key] = value
         for var in ('max_age', 'path', 'domain', 'secure', 'expires'):