diff --git a/couchpotato/core/plugins/scanner/main.py b/couchpotato/core/plugins/scanner/main.py
index bb5c7570..d466a369 100644
--- a/couchpotato/core/plugins/scanner/main.py
+++ b/couchpotato/core/plugins/scanner/main.py
@@ -385,6 +385,7 @@ class Scanner(Plugin):
             for file_type in group['files']:
                 if not file_type is 'leftover':
                     group['files']['leftover'] -= set(group['files'][file_type])
+                    group['files'][file_type] = list(group['files'][file_type])
             group['files']['leftover'] = list(group['files']['leftover'])
 
             # Delete the unsorted list