diff --git a/tempest_lib/auth.py b/tempest_lib/auth.py
index 1d23d31..0a05445 100644
--- a/tempest_lib/auth.py
+++ b/tempest_lib/auth.py
@@ -556,7 +556,7 @@ class Credentials(object):
         else:
             raise AttributeError
 
-    def get(self, item, default):
+    def get(self, item, default=None):
         # In this patch act as dict for backward compatibility
         try:
             return getattr(self, item)