diff --git a/lib/argv_split.c b/lib/argv_split.c
index e927ed0..5c35752 100644
--- a/lib/argv_split.c
+++ b/lib/argv_split.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Helper function for splitting a string into an argv-like array.
  */