diff --git a/Makefile b/Makefile
index 0719f874..b74d0d84 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 FIRMWAREDIR = /lib/firmware
 NUM_JOBS := $(or $(patsubst -j%,%,$(filter -j%,$(MAKEFLAGS))),\
 		 1)