diff --git a/drivers/usb/gadget/function/f_mtp.c b/drivers/usb/gadget/function/f_mtp.c
index aa186781ef22..5e50fe245a59 100644
--- a/drivers/usb/gadget/function/f_mtp.c
+++ b/drivers/usb/gadget/function/f_mtp.c
@@ -1876,7 +1876,8 @@ struct usb_function *function_alloc_mtp_ptp(struct usb_function_instance *fi,
 	dev->function.disable = mtp_function_disable;
 	dev->function.setup = mtp_ctrlreq_configfs;
 	dev->function.free_func = mtp_free;
-	dev->is_ptp = mtp_config;
+	dev->is_ptp = !mtp_config;
+	fi->f = &dev->function;
 
 	return &dev->function;
 }