diff --git a/django/contrib/messages/storage/cookie.py b/django/contrib/messages/storage/cookie.py
index 248791d..1ac1afe 100644
--- a/django/contrib/messages/storage/cookie.py
+++ b/django/contrib/messages/storage/cookie.py
@@ -1,7 +1,7 @@
 import hmac
 
 from django.conf import settings
-from django.utils.hashcompat import sha_constructor
+from django.utils.hashcompat import sha_hmac
 from django.contrib.messages import constants
 from django.contrib.messages.storage.base import BaseStorage, Message
 from django.utils import simplejson as json
@@ -41,7 +41,6 @@ class MessageDecoder(json.JSONDecoder):
         decoded = super(MessageDecoder, self).decode(s, **kwargs)
         return self.process_messages(decoded)
 
-
 class CookieStorage(BaseStorage):
     """
     Stores messages in a cookie.
@@ -103,7 +102,7 @@ class CookieStorage(BaseStorage):
         SECRET_KEY, modified to make it unique for the present purpose.
         """
         key = 'django.contrib.messages' + settings.SECRET_KEY
-        return hmac.new(key, value, sha_constructor).hexdigest()
+        return hmac.new(key, value, sha_hmac).hexdigest()
 
     def _encode(self, messages, encode_empty=False):
         """
diff --git a/django/utils/hashcompat.py b/django/utils/hashcompat.py
index 8880d92..b1e6021 100644
--- a/django/utils/hashcompat.py
+++ b/django/utils/hashcompat.py
@@ -8,9 +8,13 @@ available.
 try:
     import hashlib
     md5_constructor = hashlib.md5
+    md5_hmac = md5_constructor
     sha_constructor = hashlib.sha1
+    sha_hmac = sha_constructor
 except ImportError:
     import md5
     md5_constructor = md5.new
+    md5_hmac = md5
     import sha
     sha_constructor = sha.new
+    sha_hmac = sha