diff --git a/src/board/system76/common/fan.c b/src/board/system76/common/fan.c
index 979332d..7018662 100644
--- a/src/board/system76/common/fan.c
+++ b/src/board/system76/common/fan.c
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-3.0-only
+
 #include <board/fan.h>
 
 bool fan_max = false;