diff --git a/feh.1 b/feh.1
index 1dabb101a7252fb3517a92c8b7183a9a8bb54868..beec5b829357adfb881f29622c3190af0f72521e 100644
--- a/feh.1
+++ b/feh.1
@@ -260,6 +260,9 @@ below each thumbnail.
 .B -t, --thumbnails
 Same as Index mode, but the thumbnails are clickable image launchers.
 .TP 5
+.B --cache-thumbnails
+Enable thumbnail caching (in ~/.thumbnails)
+.TP 5
 .B --bg-tile FILE
 .TP 5
 .B --bg-center FILE