1 files changed, 2 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index a104078..4d311e1 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: CC0-1.0
+
 SUBDIRS=data scripts src tests
 
 recursive=all clean install