diff --git a/docs.it4i/general/accessing-the-clusters/graphical-user-interface/x-window-system.md b/docs.it4i/general/accessing-the-clusters/graphical-user-interface/x-window-system.md
index fce0586408a9b38ed1098b54e1c93a0ebfd89d3d..e6f4756b5c8634770df89cf3a21eb9c4edcf27f4 100644
--- a/docs.it4i/general/accessing-the-clusters/graphical-user-interface/x-window-system.md
+++ b/docs.it4i/general/accessing-the-clusters/graphical-user-interface/x-window-system.md
@@ -25,6 +25,8 @@ Then log in as usual.
 
 ### WSL (Bash on Windows)
 
+In order to display graphical user interface GUI of various software tools, you need to enable the X display forwarding. Log in using the -X option in ssh client:
+
 ```console
  local $ export DISPLAY=localhost:0.0
  local $ ssh -X username@cluster-name.it4i.cz