@@ -414,7 +414,7 @@ def _post_clean(self):
         # a subset of `exclude` which won't have the InlineForeignKeyField
         # if we're adding a new object since that value doesn't exist
         # until after the new instance is saved to the database.
-        construct_instance_exclude = list(exclude)
+        construct_instance_exclude = list(opts.exclude) if opts.exclude else []
 
         # Foreign Keys being used to represent inline relationships
         # are excluded from basic field value validation. This is for two