diff --git a/includes/functions.php b/includes/functions.php
index 39c0a16dd1..ac24c9e24f 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -424,7 +424,7 @@ function delete_device($id)
     // Remove sensors manually due to constraints
     foreach (dbFetchRows("SELECT * FROM `sensors` WHERE `device_id` = ?", array($id)) as $sensor) {
         $sensor_id = $sensor['sensor_id'];
-        dbDelete('sensors_to_state_indexes', "`sensor_id` = ?", array($sensor));
+        dbDelete('sensors_to_state_indexes', "`sensor_id` = ?", array($sensor_id));
     }
     $fields = array('device_id','host');
     foreach ($fields as $field) {