diff --git a/DOCS/man/en/mplayer.1 b/DOCS/man/en/mplayer.1
index 4e3ef1f40a..51f3d9c03d 100644
--- a/DOCS/man/en/mplayer.1
+++ b/DOCS/man/en/mplayer.1
@@ -904,6 +904,7 @@ i.e.\& using the shell.
 MPlayer uses this command without any checking, it is your responsibility
 to ensure it does not cause security problems (e.g.\& make sure to use full
 paths if "." is in your path like on Windows).
+It also only works when playing video (i.e. not with \-novideo but works with \-vo null).
 .sp 1
 This can be "misused" to disable screensavers that do not support the proper
 X API (also see \-stop\-xscreensaver).