diff --git a/jdownie/repo/repo b/jdownie/repo/repo
index a43bec9..95e05ed 100755
--- a/jdownie/repo/repo
+++ b/jdownie/repo/repo
@@ -73,7 +73,7 @@ def perform_action(action, key, item, silent = False):
 
 if __name__ == "__main__":
   yaml_file_path = os.getenv("REPO_CFG")
-  if not os.path.exists(yaml_file_path):
+  if yaml_file_path == None or not os.path.exists(yaml_file_path):
     print(f"Environment variable REPO_CFG needs to point to your repo.yaml file.", file=sys.stderr)
     sys.exit(1)
   try: