diff --git a/Hlt/Moore/python/Moore/qmtest/context.py b/Hlt/Moore/python/Moore/qmtest/context.py
index 0efa75dea26be0e46559e26d37d9ecf12e7a9b34..a9eeae4217cb725ae9ddd991c253975ccabcfc08 100644
--- a/Hlt/Moore/python/Moore/qmtest/context.py
+++ b/Hlt/Moore/python/Moore/qmtest/context.py
@@ -168,7 +168,7 @@ def download_digi_inputs_locally(urls, dest_dir, max_size=None):
         assertion_endswith=assertion_endswith)
 
 
-def download_mdf_inputs_locally(urls, dest_dir, max_size):
+def download_mdf_inputs_locally(urls, dest_dir, max_size=None):
     """
     Calls download_inputs_locally specifically for mdf, mep or raw files.
     """