diff --git a/lib/galaxy/webapps/galaxy/api/authenticate.py b/lib/galaxy/webapps/galaxy/api/authenticate.py
index e5c902521f0..e461930d773 100644
--- a/lib/galaxy/webapps/galaxy/api/authenticate.py
+++ b/lib/galaxy/webapps/galaxy/api/authenticate.py
@@ -94,7 +94,10 @@ class AuthenticationController(BaseAPIController):
 
         :raises: HTTPBadRequest
         """
-        split = encoded_str.strip().split(' ')
+        try:
+            split = encoded_str.strip().split(' ')
+        except AttributeError:
+            raise exceptions.RequestParameterInvalidException('Authentication is missing')
 
         # If split is only one element, try to decode the email and password
         # directly.