diff --git a/script/backup_external_repo.sh b/script/backup_external_repo.sh
index 78b36df..4226762 100755
--- a/script/backup_external_repo.sh
+++ b/script/backup_external_repo.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #
 # Copyright (c) 2019, Arm Limited. All rights reserved.
 #