diff --git a/tempest/auth.py b/tempest/auth.py
index 022a450..2550cfb 100644
--- a/tempest/auth.py
+++ b/tempest/auth.py
@@ -561,7 +561,10 @@
             raise exceptions.InvalidCredentials()
         creds = cls._get_default(credentials_type)
         if not creds.is_valid():
-            raise exceptions.InvalidConfiguration()
+            msg = ("The %s credentials are incorrectly set in the config file."
+                   " Double check that all required values are assigned" %
+                   credentials_type)
+            raise exceptions.InvalidConfiguration(msg)
         return creds
 
     @classmethod