diff --git a/include/linux/err.h b/include/linux/err.h
index 1e35588..87be243 100644
--- a/include/linux/err.h
+++ b/include/linux/err.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_ERR_H
 #define _LINUX_ERR_H