diff --git a/html/ops/delete_spammers.php b/html/ops/delete_spammers.php
index e238940915..b9dd372f50 100755
--- a/html/ops/delete_spammers.php
+++ b/html/ops/delete_spammers.php
@@ -263,6 +263,9 @@ function delete_users($no_hosts, $no_posts, $no_teams, $have_url) {
     $n = 0;
     while ($u = $result->fetch_object()) {
         $user = BoincUser::lookup_id($u->id);
+        if (!$user) {
+            continue;
+        }
         if ($have_url) {
             if (!strlen($user->url)) continue;
         }