diff --git a/ChangeLog b/ChangeLog
index 1943d84c..a1b6578b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-07-30  Lukáš Kuklínek  <lkukline@redhat.com>
+
+	* src/groupmems.c: Only check if the adduser user exists when an
+	user is specified with -a.
+
 2008-07-30  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/groupmems.c: Fix the groupmems' usage message. The -D option
diff --git a/src/groupmems.c b/src/groupmems.c
index 48ed34fc..e4948a23 100644
--- a/src/groupmems.c
+++ b/src/groupmems.c
@@ -163,7 +163,8 @@ static void process_flags (int argc, char **argv)
 	}
 
 	/* local, no need for xgetpwnam */
-	if (getpwnam (adduser) == NULL) {
+	if (   (NULL != adduser)
+	    && (getpwnam (adduser) == NULL)) {
 		fprintf (stderr, _("%s: user `%s' does not exist\n"),
 		         Prog, adduser);
 		fail_exit (EXIT_INVALID_USER);