diff --git a/flatland/envs/predictions.py b/flatland/envs/predictions.py
index 7483ebadf07a999f16b4e8056ae9c841ab3db9f6..88a79ea72606e7c1b46f92f6d73429979d67a4e6 100644
--- a/flatland/envs/predictions.py
+++ b/flatland/envs/predictions.py
@@ -87,6 +87,7 @@ class ShortestPathPredictorForRailEnv(PredictionBuilder):
     """
 
     def __init__(self, max_depth=20):
+        # Initialize with depth 20
         self.max_depth = max_depth
 
     def get(self, custom_args=None, handle=None):