diff --git a/novaclient/base.py b/novaclient/base.py
index 431ac7d6f..821e19bd9 100644
--- a/novaclient/base.py
+++ b/novaclient/base.py
@@ -307,8 +307,8 @@ class Manager(HookableMixin):
             # endpoint pair
             username = utils.env('OS_USERNAME', 'NOVA_USERNAME')
             url = utils.env('OS_URL', 'NOVA_URL')
-            uniqifier = hashlib.md5(username.encode('utf-8') +
-                                    url.encode('utf-8')).hexdigest()
+            uniqifier = hashlib.sha256(username.encode('utf-8') +
+                                       url.encode('utf-8')).hexdigest()
 
             cache_dir = os.path.expanduser(os.path.join(base_dir, uniqifier))