diff --git a/Setup/README.md b/Setup/README.md
index 121d3b1a82057536c479f49fdbd2441f6fc6fb03..cb43bb2d204a37d7c0ce0f61667c3d66030e96ee 100644
--- a/Setup/README.md
+++ b/Setup/README.md
@@ -21,7 +21,8 @@ Adding yourself to the docker group can by done by running
 
     sudo gpasswd -a <username> docker
 
-where <username> is to be replaced by your user name.
+where <username> is to be replaced by your user name. Don't forget to log out and back in again, to make 
+the change effective.
 
 On `systemd`-based systems the daemon is started by running