diff --git a/app/hot_desking/extension_delete.php b/app/hot_desking/extension_delete.php
index 2ae31a355f..d17ab2df0a 100644
--- a/app/hot_desking/extension_delete.php
+++ b/app/hot_desking/extension_delete.php
@@ -41,7 +41,10 @@ if (count($_GET)>0) {
 //delete the extension
 	if (strlen($id)>0) {
 		$sql .= "update v_extensions ";
-		$sql .= "set unique_id = null ";
+		$sql .= "set unique_id = null, ";
+		$sql .= "dial_user = null, ";
+		$sql .= "dial_domain = null, ";
+		$sql .= "dial_string = null ";
 		$sql .= "where domain_uuid = '$domain_uuid' ";
 		$sql .= "and extension_uuid = '$id' ";
 		$prep_statement = $db->prepare(check_sql($sql));