Remaining fixes to make Python tests pass in google3.
diff --git a/python/message.c b/python/message.c
index 11b3a08..095f56d 100644
--- a/python/message.c
+++ b/python/message.c
@@ -1482,6 +1482,7 @@
                                                  void* closure) {
   PyUpb_CMessage* self = (void*)_self;
   if (self->ext_dict) {
+    Py_INCREF(self->ext_dict);
     return self->ext_dict;
   }