diff --git a/net/ceph/string_table.c b/net/ceph/string_table.c
index 22fb96e..3191d9d 100644
--- a/net/ceph/string_table.c
+++ b/net/ceph/string_table.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include <linux/slab.h>
 #include <linux/gfp.h>
 #include <linux/string.h>