diff --git a/flatland/envs/rail_env.py b/flatland/envs/rail_env.py
index 5dc9e8d6df20a7be22fdac7297f22619789575be..9000aaa96ce25f8de0308be9ceb0c406cc522275 100644
--- a/flatland/envs/rail_env.py
+++ b/flatland/envs/rail_env.py
@@ -130,7 +130,7 @@ class RailEnv(Environment):
             vectors for each agent.
         max_episode_steps : int or None
 
-        file_name: you can load a pickle file.
+        file_name: you can load a pickle file. from previously saved *.pkl file
 
         """