diff --git a/flatland/contrib/wrappers/flatland_wrappers.py b/flatland/contrib/wrappers/flatland_wrappers.py
index ce3b2a232d7b1dfdb2c7da3bd8c3638cf57fdb3b..500f3d2e657af810fd0144cacf3b7a201284a003 100644
--- a/flatland/contrib/wrappers/flatland_wrappers.py
+++ b/flatland/contrib/wrappers/flatland_wrappers.py
@@ -8,6 +8,7 @@ from flatland.utils.rendertools import RenderTool, AgentRenderVariant
 from flatland.envs.agent_utils import EnvAgent
 from flatland.envs.step_utils.states import TrainState
 from flatland.envs.rail_env import RailEnv, RailEnvActions
+from flatland.contrib.utils.deadlock_checker import Deadlock_Checker
 
 
 def possible_actions_sorted_by_distance(env: RailEnv, handle: int):