diff --git a/flatland/utils/rendertools.py b/flatland/utils/rendertools.py
index 0ce87ff91dd8e19faee1554a89fb80ec7eecbac4..d97f71637ca769579f1e2bdfe12aeafd8d2db5cd 100644
--- a/flatland/utils/rendertools.py
+++ b/flatland/utils/rendertools.py
@@ -9,6 +9,7 @@ from collections import deque
 
 # TODO: suggested renaming to RailEnvRenderTool, as it will only work with RailEnv!
 
+
 class RenderTool(object):
     Visit = recordtype("Visit", ["rc", "iDir", "iDepth", "prev"])