diff --git a/ChangeLog b/ChangeLog
index 56c2ecb2..5d5929bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-02-10  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* NEWS, src/usermod.c: Fix the handling of -a when a user is being
+	renamed (with -l). The new name of the user was used for the new
+	supplementary groups, but not in the existing ones.
+
 2008-02-10  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/newusers.c: Set the shadow's password instead of the
diff --git a/NEWS b/NEWS
index 0d853b99..1aad2984 100644
--- a/NEWS
+++ b/NEWS
@@ -65,6 +65,7 @@ shadow-4.1.0 -> shadow-4.1.1						UNRELEASED
     one, no changes will be performed for that field. If no fields are
     changed, usermod will exist successfully with a warning. This avoids
     logging changes to syslog when there are actually no changes.
+  * Fix the handling of -a when a user is being renamed (with -l)
 - vipw/vigr
   * Recommend editing the shadowed (resp. regular) file if the regular (resp.
     shadowed) file was edited.
diff --git a/src/usermod.c b/src/usermod.c
index 5246650a..1ff4fc86 100644
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -533,7 +533,8 @@ static void update_group (void)
 		 * concurrent groups.
 		 */
 		was_member = is_on_list (grp->gr_mem, user_name);
-		is_member = Gflg && is_on_list (user_groups, grp->gr_name);
+		is_member = Gflg && (   (was_member && aflg)
+		                     || is_on_list (user_groups, grp->gr_name));
 
 		if (!was_member && !is_member)
 			continue;
@@ -629,6 +630,8 @@ static void update_gshadow (void)
 		 * concurrent groups.
 		 */
 		is_member = Gflg && is_on_list (user_groups, sgrp->sg_name);
+		is_member = Gflg && (   (was_member && aflg)
+		                     || is_on_list (user_groups, sgrp->sg_name));
 
 		if (!was_member && !was_admin && !is_member)
 			continue;