diff --git a/sys/libkern/strstr.c b/sys/libkern/strstr.c
index b7494f3235da..1454fbe0c705 100644
--- a/sys/libkern/strstr.c
+++ b/sys/libkern/strstr.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-4-Clause
+ * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.