diff --git a/rl_coach/logger.py b/rl_coach/logger.py
index 4812a44..37cc856 100644
--- a/rl_coach/logger.py
+++ b/rl_coach/logger.py
@@ -313,7 +313,7 @@ class Logger(BaseLogger):
 #######################################################################################################################
 
 global experiment_path
-experiment_path = None
+experiment_path = ""
 
 global experiment_name
 experiment_name = None