diff --git a/man2/mkdir.2 b/man2/mkdir.2
index 22523915c..10242e69d 100644
--- a/man2/mkdir.2
+++ b/man2/mkdir.2
@@ -6,7 +6,7 @@
 .\" You may distribute it under the terms of the GNU General
 .\" Public License. It comes with NO WARRANTY.
 .\"
-.TH MKDIR 2 2003-12-09 "Linux" "Linux Programmer's Manual"
+.TH MKDIR 2 2008-05-13 "Linux" "Linux Programmer's Manual"
 .SH NAME
 mkdir \- create a directory
 .SH SYNOPSIS
@@ -35,8 +35,11 @@ For Linux, see below.
 The newly created directory will be owned by the effective user ID of the
 process.
 If the directory containing the file has the set-group-ID
-bit set, or if the file system is mounted with BSD group semantics, the
-new directory will inherit the group ownership from its parent;
+bit set, or if the file system is mounted with BSD group semantics
+.RI ( "mount -o bsdgroups"
+or, synonymously
+.IR "mount -o grpid" ),
+the new directory will inherit the group ownership from its parent;
 otherwise it will be owned by the effective group ID of the process.
 
 If the parent directory has the set-group-ID bit set then so will the