diff --git a/DOCS/man/en/mplayer.1 b/DOCS/man/en/mplayer.1
index 591813774c..fc9b9baf00 100644
--- a/DOCS/man/en/mplayer.1
+++ b/DOCS/man/en/mplayer.1
@@ -2333,6 +2333,8 @@ Considered obsolete.
 .B sdl (SDL only)
 Highly platform independent SDL (Simple Directmedia Layer) library
 video output driver.
+Since SDL uses its own X11 layer, MPlayer X11 options do not have
+any effect on SDL.
 .
 .TP
 .B vidix\ \