diff --git a/src/main.cc b/src/main.cc
index e68ea7c..f1075f2 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -1,3 +1,20 @@
+/*
+spnavcfg - an interactive GUI configurator for the spacenavd daemon.
+Copyright (C) 2007-2022 John Tsiombikas <nuclear@siggraph.org>
+
+This program 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.
+
+This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
 #include <QApplication>
 #include <QSocketNotifier>
 #define SPNAV_CONFIG_H_
diff --git a/src/spnavcfg.c b/src/spnavcfg.c
index ad388fd..d1220a5 100644
--- a/src/spnavcfg.c
+++ b/src/spnavcfg.c
@@ -1,3 +1,20 @@
+/*
+spnavcfg - an interactive GUI configurator for the spacenavd daemon.
+Copyright (C) 2007-2022 John Tsiombikas <nuclear@siggraph.org>
+
+This program 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.
+
+This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
 #include <stdlib.h>
 #include <string.h>
 #include <spnav.h>
diff --git a/src/spnavcfg.h b/src/spnavcfg.h
index 2a5921f..c9f922d 100644
--- a/src/spnavcfg.h
+++ b/src/spnavcfg.h
@@ -1,3 +1,20 @@
+/*
+spnavcfg - an interactive GUI configurator for the spacenavd daemon.
+Copyright (C) 2007-2022 John Tsiombikas <nuclear@siggraph.org>
+
+This program 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.
+
+This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
 #ifndef SPNAVCFG_H_
 #define SPNAVCFG_H_
 
diff --git a/src/ui.cc b/src/ui.cc
index 7935955..c9d7feb 100644
--- a/src/ui.cc
+++ b/src/ui.cc
@@ -1,3 +1,20 @@
+/*
+spnavcfg - an interactive GUI configurator for the spacenavd daemon.
+Copyright (C) 2007-2022 John Tsiombikas <nuclear@siggraph.org>
+
+This program 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.
+
+This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
 #include <stdio.h>
 #include <assert.h>
 #define SPNAV_CONFIG_H_
diff --git a/src/ui.h b/src/ui.h
index f1dcbac..0f04e3a 100644
--- a/src/ui.h
+++ b/src/ui.h
@@ -1,3 +1,20 @@
+/*
+spnavcfg - an interactive GUI configurator for the spacenavd daemon.
+Copyright (C) 2007-2022 John Tsiombikas <nuclear@siggraph.org>
+
+This program 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.
+
+This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
 #ifndef UI_H_
 #define UI_H_