4 files changed, 12 insertions, 0 deletions
diff --git a/Readme.md b/Readme.md
index b932d85..f75e51a 100644
--- a/Readme.md
+++ b/Readme.md
@@ -68,6 +68,9 @@ Authors:
 This is free and unencumbered software released into the public domain. See
 ``UNLICENSE`` for more information.
 
+This repository includes source code of other projects:
+- Optparse ([gh:skeeto/optparse](https://github.com/skeeto/optparse)) - Unlicense
+
 Resources used to implement the disassember (this set is more than sufficient to
 support all of M68000 instructions):
 - [The 68000's Instruction Set](http://wpage.unina.it/rcanonic/didattica/ce1/docs/68000.pdf) - Appendix of an unrecognized book. Basically the same information also could be found in [gh:prb28/m68k-instructions-documentation](https://github.com/prb28/m68k-instructions-documentation).
diff --git a/common.h b/common.h
index fbd73de..0f96cc3 100644
--- a/common.h
+++ b/common.h
@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: Unlicense
+ */
+
 #pragma once
 
 struct Settings {
diff --git a/disasm.cpp b/disasm.cpp
index 582bbd9..45b0def 100644
--- a/disasm.cpp
+++ b/disasm.cpp
@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: Unlicense
+ */
+
 #include "disasm.h"
 #include "data_buffer.h"
 #include "common.h"
diff --git a/disasm.h b/disasm.h
index 5e9ad3b..7c40438 100644
--- a/disasm.h
+++ b/disasm.h
@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: Unlicense
+ */
+
 #pragma once
 
 #include "data_buffer.h"