diff --git a/rel/files/vm.args b/rel/files/vm.args
index 19a9dbfa0..3e9784935 100644
--- a/rel/files/vm.args
+++ b/rel/files/vm.args
@@ -7,9 +7,9 @@
 -setcookie emqttdsecretcookie
 
 ##-------------------------------------------------------------------------
-## Mnesia db
+## Mnesia dir. NOTICE: quote the dir with '" "'
 ##-------------------------------------------------------------------------
--mnesia dir "data/mnesia/test"
+-mnesia dir '"data/mnesia"'
 
 ##-------------------------------------------------------------------------
 ## Flags