diff --git a/README.md b/README.md
index 064246d..ea700a5 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ and videos (see [Previews](#previews)).
 
 Image previews are powered by one of these:
 
-* [Überzug](https://github.com/seebye/ueberzug)
+* [Überzug](https://github.com/seebye/ueberzug) (X11 only)
 * [Kitty terminal](https://github.com/kovidgoyal/kitty)
 * [Chafa](https://github.com/hpjansson/chafa)
 
diff --git a/doc/ctpv.1 b/doc/ctpv.1
index d612dbf..1bbda37 100644
--- a/doc/ctpv.1
+++ b/doc/ctpv.1
@@ -9,7 +9,7 @@ ctpv \- terminal previewer
 .SH SYNOPSIS
 .
 .SY ctpv
-.I file
+.I  file
 .RI [ w ]
 .RI [ h ]
 .RI [ x ]
@@ -164,6 +164,15 @@ or
 options (see
 .IR "Preview options" ).
 .
+.PP
+Note that
+.I \*(ub
+supports
+.I X11
+only
+.RI ( Wayland
+is not supported).
+.
 .SS How previews are selected
 .
 Initially,