diff --git a/html/includes/api_functions.inc.php b/html/includes/api_functions.inc.php
index 1761cabf2..68a574a59 100644
--- a/html/includes/api_functions.inc.php
+++ b/html/includes/api_functions.inc.php
@@ -925,7 +925,7 @@ function list_bills() {
         $param = array($bill_ref);
     }
     elseif (is_numeric($bill_id)) {
-        $sql   = '`bill_id` = ?';
+        $sql   = '`bills`.`bill_id` = ?';
         $param = array($bill_id);
     }
     else {