1 files changed, 2 insertions, 0 deletions
diff --git a/ops/sub.c b/ops/sub.c
index 47c2bfe..38cccef 100644
--- a/ops/sub.c
+++ b/ops/sub.c
@@ -1,3 +1,5 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+
 #include "common.h"
 
 DEFINE_OP(sub)