diff --git a/kernel/ethosu_device.c b/kernel/ethosu_device.c
index 1a2e7f7..ae257c3 100644
--- a/kernel/ethosu_device.c
+++ b/kernel/ethosu_device.c
@@ -522,7 +522,10 @@
 
 	dev_info(dev, "%s", __FUNCTION__);
 
+	device_lock(&edev->dev);
 	ethosu_mailbox_fail(&edev->mailbox);
+	device_unlock(&edev->dev);
+
 	rpmsg_destroy_ept(edev->ept);
 	cdev_del(&edev->cdev);
 	device_unregister(&edev->dev);