diff --git a/demo/start.sh b/demo/start.sh
index e426094994..28ea1b1cb6 100755
--- a/demo/start.sh
+++ b/demo/start.sh
@@ -8,7 +8,8 @@ cd "$DIR/.." || exit
 
 mkdir -p demo/etc
 
-export PYTHONPATH=$(readlink -f "$(pwd)")
+PYTHONPATH=$(readlink -f "$(pwd)")
+export PYTHONPATH
 
 
 echo $PYTHONPATH