diff --git a/ChangeLog b/ChangeLog
index 2b335692..7b464e7d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-06-13  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* src/groups.c: sys_ngroups is only used when HAVE_GETGROUPS is
+	defined.
+
 2008-06-13  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/faillog.c: Ignore return value of time() when use with a
diff --git a/src/groups.c b/src/groups.c
index df9650c8..f7bbe5cd 100644
--- a/src/groups.c
+++ b/src/groups.c
@@ -106,9 +106,8 @@ static void print_groups (const char *member)
  */
 int main (int argc, char **argv)
 {
-	long sys_ngroups;
-
 #ifdef HAVE_GETGROUPS
+	long sys_ngroups;
 	int ngroups;
 	GETGROUPS_T *groups;
 	int pri_grp; /* TODO: should be GETGROUPS_T */
@@ -118,9 +117,9 @@ int main (int argc, char **argv)
 	char *getlogin ();
 #endif
 
-	sys_ngroups = sysconf (_SC_NGROUPS_MAX);
 #ifdef HAVE_GETGROUPS
-	groups = (GETGROUPS_T *) malloc (sys_ngroups * sizeof (GETGROUPS_T));
+	sys_ngroups = sysconf (_SC_NGROUPS_MAX);
+	groups = (GETGROUPS_T *) malloc (sizeof (GETGROUPS_T) * sys_ngroups);
 #endif
 	(void) setlocale (LC_ALL, "");
 	(void) bindtextdomain (PACKAGE, LOCALEDIR);