diff --git a/phpBB/includes/acp/acp_groups.php b/phpBB/includes/acp/acp_groups.php
index 486616c33d..bbe85f8038 100644
--- a/phpBB/includes/acp/acp_groups.php
+++ b/phpBB/includes/acp/acp_groups.php
@@ -179,6 +179,10 @@ class acp_groups
 			break;
 
 			case 'deleteusers':
+				if (empty($mark_ary))
+				{
+					trigger_error($user->lang['NO_USERS'] . adm_back_link($this->u_action . '&action=list&g=' . $group_id), E_USER_WARNING);
+				}
 			case 'delete':
 				if (!$group_id)
 				{
@@ -795,4 +799,4 @@ class acp_groups
 	}
 }
 
-?>
\ No newline at end of file
+?>