diff --git a/flatland/envs/observations.py b/flatland/envs/observations.py
index 4d32faa42c17d3f7bfe908b631c02fc29a1ef2f2..e6b7a4f0b4ad84e6b07aa9395efc0aae2c5e5451 100644
--- a/flatland/envs/observations.py
+++ b/flatland/envs/observations.py
@@ -191,7 +191,7 @@ class TreeObsForRailEnv(ObservationBuilder):
 
         #7: agent in the opposite drection
             1 = agent present other direction than myself (so conflict)
-                (possible future use: number of other agents in other direction in this branch, i.e. number of conflicts)
+                (possible future use: number of other agents in other direction in this branch, ie. number of conflicts)
             0 = no agent present other direction than myself