diff --git a/man/mshow.1 b/man/mshow.1
index 992a0dc..b8e2ca7 100644
--- a/man/mshow.1
+++ b/man/mshow.1
@@ -91,6 +91,9 @@ into files.
 can be specified by number, filename or
 .Xr fnmatch 3
 pattern.
+If no
+.Ar parts
+are specified, extracts all attachments with a filename.
 .It Fl O Ar msg
 Like
 .Fl x