diff --git a/keystone/common/fernet_utils.py b/keystone/common/fernet_utils.py
index 9188dfbfc6..928c2488d1 100644
--- a/keystone/common/fernet_utils.py
+++ b/keystone/common/fernet_utils.py
@@ -36,8 +36,8 @@ NULL_KEY = base64.urlsafe_b64encode(b'\x00' * 32)
 
 class FernetUtils(object):
 
-    def __init__(self, key_repository=None, max_active_keys=None,
-                 config_group=None):
+    def __init__(self, key_repository, max_active_keys,
+                 config_group):
         self.key_repository = key_repository
         self.max_active_keys = max_active_keys
         self.config_group = config_group
diff --git a/keystone/credential/providers/fernet/core.py b/keystone/credential/providers/fernet/core.py
index 5c3e43e55c..411f0a4064 100644
--- a/keystone/credential/providers/fernet/core.py
+++ b/keystone/credential/providers/fernet/core.py
@@ -97,7 +97,7 @@ class Provider(core.Provider):
         :returns: a decrypted credential
         """
         key_utils = fernet_utils.FernetUtils(
-            CONF.credential.key_repository, MAX_ACTIVE_KEYS)
+            CONF.credential.key_repository, MAX_ACTIVE_KEYS, 'credential')
         keys = key_utils.load_keys(use_null_key=True)
         fernet_keys = [fernet.Fernet(key) for key in keys]
         crypto = fernet.MultiFernet(fernet_keys)