diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index e554a22..bacab6e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -1,3 +1,24 @@
+#           __        _
+#  ________/ /  ___ _(_)__  ___
+# / __/ __/ _ \/ _ `/ / _ \/ -_)
+# \__/\__/_//_/\_,_/_/_//_/\__/
+# 
+# Copyright (C) Clément Chaine
+# This file is part of verilator-cmake <https://github.com/ecap5/verilator-cmake>
+# 
+# verilator-cmake is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# verilator-cmake is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with verilator-cmake.  If not, see <http://www.gnu.org/licenses/>.
+
 name: Tests
 
 on:
diff --git a/cmake/verilator-config.cmake b/cmake/verilator-config.cmake
index 62889a6..89d38af 100644
--- a/cmake/verilator-config.cmake
+++ b/cmake/verilator-config.cmake
@@ -1,3 +1,24 @@
+#           __        _
+#  ________/ /  ___ _(_)__  ___
+# / __/ __/ _ \/ _ `/ / _ \/ -_)
+# \__/\__/_//_/\_,_/_/_//_/\__/
+# 
+# Copyright (C) Clément Chaine
+# This file is part of verilator-cmake <https://github.com/ecap5/verilator-cmake>
+# 
+# verilator-cmake is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# verilator-cmake is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with verilator-cmake.  If not, see <http://www.gnu.org/licenses/>.
+
 ######################################################################
 #
 # DESCRIPTION: CMake configuration file for Verilator
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index f021c35..493331c 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,3 +1,24 @@
+#           __        _
+#  ________/ /  ___ _(_)__  ___
+# / __/ __/ _ \/ _ `/ / _ \/ -_)
+# \__/\__/_//_/\_,_/_/_//_/\__/
+# 
+# Copyright (C) Clément Chaine
+# This file is part of verilator-cmake <https://github.com/ecap5/verilator-cmake>
+# 
+# verilator-cmake is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# verilator-cmake is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with verilator-cmake.  If not, see <http://www.gnu.org/licenses/>.
+
 cmake_minimum_required(VERSION 3.12)
 
 project(verilator-cmake-test VERSION 1.0)
diff --git a/tests/src/top.sv b/tests/src/top.sv
index 7261aa9..3ef8788 100644
--- a/tests/src/top.sv
+++ b/tests/src/top.sv
@@ -1,3 +1,25 @@
+/*           __        _
+ *  ________/ /  ___ _(_)__  ___
+ * / __/ __/ _ \/ _ `/ / _ \/ -_)
+ * \__/\__/_//_/\_,_/_/_//_/\__/
+ * 
+ * Copyright (C) Clément Chaine
+ * This file is part of verilator-cmake <https://github.com/ecap5/verilator-cmake>
+ *
+ * verilator-cmake is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * verilator-cmake is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with verilator-cmake.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 module top (
   input   logic        clk_i,     
   output  logic        clk_o