diff --git a/fancy_gym/envs/registry.py b/fancy_gym/envs/registry.py
index 9cf2135..862f24d 100644
--- a/fancy_gym/envs/registry.py
+++ b/fancy_gym/envs/registry.py
@@ -141,7 +141,7 @@ def upgrade(
         mp_wrapper=mp_wrapper,
         register_step_based=False,
         add_mp_types=add_mp_types,
-        mp_config_override={},
+        mp_config_override=mp_config_override,
         **kwargs
     )