diff --git a/Makefile b/Makefile
index af80e1d..8c29d64 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,8 @@
+# Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
+# This work is free. You can redistribute it and/or modify it under the
+# terms of the Do What The Fuck You Want To Public License, Version 2,
+# as published by Sam Hocevar. See the COPYING file for more details.
+
 CFLAGS = -g -Wall -Wextra -Werror
 LDFLAGS = -lcheck
 
diff --git a/example.c b/example.c
index c1b67e3..49ce9c9 100644
--- a/example.c
+++ b/example.c
@@ -1,3 +1,10 @@
+/*
+ * Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
+ * This work is free. You can redistribute it and/or modify it under the
+ * terms of the Do What The Fuck You Want To Public License, Version 2,
+ * as published by Sam Hocevar. See the COPYING file for more details.
+ */
+
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>
diff --git a/minmea.c b/minmea.c
index 89c6be8..bd6fb06 100644
--- a/minmea.c
+++ b/minmea.c
@@ -1,3 +1,10 @@
+/*
+ * Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
+ * This work is free. You can redistribute it and/or modify it under the
+ * terms of the Do What The Fuck You Want To Public License, Version 2,
+ * as published by Sam Hocevar. See the COPYING file for more details.
+ */
+
 #include "minmea.h"
 
 #include <stdlib.h>
diff --git a/minmea.h b/minmea.h
index f282455..94249ae 100644
--- a/minmea.h
+++ b/minmea.h
@@ -1,3 +1,10 @@
+/*
+ * Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
+ * This work is free. You can redistribute it and/or modify it under the
+ * terms of the Do What The Fuck You Want To Public License, Version 2,
+ * as published by Sam Hocevar. See the COPYING file for more details.
+ */
+
 #ifndef MINMEA_H
 #define MINMEA_H
 
diff --git a/tests.c b/tests.c
index ae8e5d9..1744a3c 100644
--- a/tests.c
+++ b/tests.c
@@ -1,3 +1,10 @@
+/*
+ * Copyright © 2014 Kosma Moczek <kosma@cloudyourcar.com>
+ * This work is free. You can redistribute it and/or modify it under the
+ * terms of the Do What The Fuck You Want To Public License, Version 2,
+ * as published by Sam Hocevar. See the COPYING file for more details.
+ */
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>