--- Main.php.org	2018-03-18 22:18:00.000000000 +0100
+++ Main.php	2018-04-09 07:58:07.767855400 +0200
@@ -80,7 +80,12 @@
              $this->db->query('TRUNCATE '.$this->table.'cache');
              $this->db->query('TRUNCATE '.$this->table.'oldlinks');
          } else {
-            $this->db->query('DELETE FROM '.$this->table.'cache WHERE sticky != 1');
+            $this->db->query('DELETE '.$this->table.'cache.* FROM '
+                             .$this->table.'cache LEFT JOIN '.$this->table.'oldlinks ON '
+                             .$this->table.'cache.id = '.$this->table.'oldlinks.link_id WHERE '
+                             .$this->table.'cache.sticky != 1 AND ('
+                             .$this->table.'oldlinks.sticky != 1 OR '
+                             .$this->table.'oldlinks.sticky IS NULL)');
             $this->db->query('DELETE FROM '.$this->table.'oldlinks WHERE sticky != 1');
          }
       }