diff --git a/README.md b/README.md
index 1cb7075f..981a6c19 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@ __(formerly kconfig-hardened-check)__
[![functional test coverage](https://codecov.io/gh/a13xp0p0v/kernel-hardening-checker/graph/badge.svg?flag=functional_test)](https://app.codecov.io/gh/a13xp0p0v/kernel-hardening-checker?flags%5B0%5D=functional_test)
[![engine unit-test](https://github.com/a13xp0p0v/kernel-hardening-checker/workflows/engine%20unit-test/badge.svg)](https://github.com/a13xp0p0v/kernel-hardening-checker/actions/workflows/engine_unit-test.yml)
[![unit-test coverage](https://codecov.io/gh/a13xp0p0v/kernel-hardening-checker/graph/badge.svg?flag=engine_unit-test)](https://app.codecov.io/gh/a13xp0p0v/kernel-hardening-checker?flags%5B0%5D=engine_unit-test)
+[![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)
[![GitHub tag (latest by date)](https://img.shields.io/github/v/tag/a13xp0p0v/kernel-hardening-checker?label=release)](https://github.com/a13xp0p0v/kernel-hardening-checker/tags)
## Motivation
@@ -15,7 +16,9 @@ make our systems more secure.
But nobody likes checking configs manually. So let the computers do their job!
-__kernel-hardening-checker__ (formerly __kconfig-hardened-check__) is a tool for checking the security hardening options of the Linux kernel. It supports checking:
+__kernel-hardening-checker__ (formerly __kconfig-hardened-check__) is a tool for checking the security hardening options of the Linux kernel. License: GPL-3.0.
+
+The tool supports checking:
- Kconfig options (compile-time)
- Kernel cmdline arguments (boot-time)
diff --git a/bin/kernel-hardening-checker b/bin/kernel-hardening-checker
index 8a5cd89b..214f30f9 100755
--- a/bin/kernel-hardening-checker
+++ b/bin/kernel-hardening-checker
@@ -1,6 +1,13 @@
#!/usr/bin/env python3
-# For using the tool without installation via setuptools
+"""
+This tool is for checking the security hardening options of the Linux kernel.
+
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
+
+This file is for using the tool without installation via setuptools.
+"""
import os
import sys
diff --git a/kernel_hardening_checker/__init__.py b/kernel_hardening_checker/__init__.py
index 043dae8c..487eff45 100755
--- a/kernel_hardening_checker/__init__.py
+++ b/kernel_hardening_checker/__init__.py
@@ -3,7 +3,8 @@
"""
This tool is for checking the security hardening options of the Linux kernel.
-Author: Alexander Popov
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
This module performs input/output.
"""
diff --git a/kernel_hardening_checker/checks.py b/kernel_hardening_checker/checks.py
index be2689e0..0bc183bf 100755
--- a/kernel_hardening_checker/checks.py
+++ b/kernel_hardening_checker/checks.py
@@ -3,7 +3,8 @@
"""
This tool is for checking the security hardening options of the Linux kernel.
-Author: Alexander Popov
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
This module contains knowledge for checks.
"""
diff --git a/kernel_hardening_checker/engine.py b/kernel_hardening_checker/engine.py
index ee56d637..39f54c54 100755
--- a/kernel_hardening_checker/engine.py
+++ b/kernel_hardening_checker/engine.py
@@ -3,7 +3,8 @@
"""
This tool is for checking the security hardening options of the Linux kernel.
-Author: Alexander Popov
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
This module is the engine of checks.
"""
diff --git a/kernel_hardening_checker/test_engine.py b/kernel_hardening_checker/test_engine.py
index 05e640c9..50328cab 100755
--- a/kernel_hardening_checker/test_engine.py
+++ b/kernel_hardening_checker/test_engine.py
@@ -3,7 +3,8 @@
"""
This tool is for checking the security hardening options of the Linux kernel.
-Author: Alexander Popov
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
This module performs unit-testing of the kernel-hardening-checker engine.
"""
diff --git a/setup.py b/setup.py
index 127bfae2..f8fac99d 100755
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,8 @@
"""
This tool is for checking the security hardening options of the Linux kernel.
-Author: Alexander Popov
+SPDX-FileCopyrightText: Alexander Popov
+SPDX-License-Identifier: GPL-3.0-only
This module performs installing of the kernel-hardening-checker package.
"""