diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h
index 2821b86..d751212 100644
--- a/include/trace/events/lock.h
+++ b/include/trace/events/lock.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM lock