1 files changed, 4 insertions, 2 deletions
diff --git a/python/google/protobuf/internal/python_message.py b/python/google/protobuf/internal/python_message.py
index c0d0ad45..60b4baad 100755
--- a/python/google/protobuf/internal/python_message.py
+++ b/python/google/protobuf/internal/python_message.py
@@ -380,13 +380,15 @@ def _GetInitializeDefaultForMap(field):
   if _IsMessageMapField(field):
     def MakeMessageMapDefault(message):
       return containers.MessageMap(
-          message._listener_for_children, value_field.message_type, key_checker)
+          message._listener_for_children, value_field.message_type, key_checker,
+          field.message_type)
     return MakeMessageMapDefault
   else:
     value_checker = type_checkers.GetTypeChecker(value_field)
     def MakePrimitiveMapDefault(message):
       return containers.ScalarMap(
-          message._listener_for_children, key_checker, value_checker)
+          message._listener_for_children, key_checker, value_checker,
+          field.message_type)
     return MakePrimitiveMapDefault
 
 def _DefaultValueConstructorForField(field):