diff --git a/sites/all/modules/simple_cart/simple_cart.module b/sites/all/modules/simple_cart/simple_cart.module
--- a/sites/all/modules/simple_cart/simple_cart.module
+++ b/sites/all/modules/simple_cart/simple_cart.module
@@ -149,7 +149,7 @@
  */
 function simple_cart_cron() {
   // Fetch list of outdated sids.
-  $sql = "SELECT sc.sid FROM {%s} sc LEFT JOIN {sessions} s ON (sc.session_id = s.sid) WHERE s.sid IS NULL";
+  $sql = "SELECT sc.sid FROM {%s} sc LEFT JOIN {sessions} s ON (sc.sid = s.sid) WHERE s.sid IS NULL";
   $result = db_query($sql, SIMPLE_CART_TABLE_NAME);
   $outdated_sids = array();
   while ($session = db_fetch_object($result)) {