diff --git a/fief/forms.py b/fief/forms.py
index 576ed77a..93e9a71e 100644
--- a/fief/forms.py
+++ b/fief/forms.py
@@ -222,7 +222,7 @@ def _choices_generator(self, choices):
 
         for value, label in _choices:
             selected = value in data_values
-            yield (value, label, selected)
+            yield (value, label, selected, {})
 
     def process_data(self, value):
         try: