diff --git a/sys/man/1/tar b/sys/man/1/tar
index da79167dd..aaafcb683 100644
--- a/sys/man/1/tar
+++ b/sys/man/1/tar
@@ -195,6 +195,10 @@ The
 key (append)
 cannot be used on compressed archives.
 .PP
+The
+.B T
+key (write metadata) won't work for non-empty directories.
+.PP
 .IR Tar ,
 thus
 .IR dircp ,