diff --git a/src/pam.c b/src/pam.c
index 43791130..1cba9169 100644
--- a/src/pam.c
+++ b/src/pam.c
@@ -1,3 +1,20 @@
+/*
+ * Copyright (c) 2003-2007 Andrea Luzzardi <scox@sig11.org>
+ *
+ * This file is part of the pam_usb project. pam_usb is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU General
+ * Public License version 2, as published by the Free Software Foundation.
+ *
+ * pam_usb 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, write to the Free Software Foundation, Inc., 51 Franklin
+ * Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
 #define PAM_SM_AUTH
 #include <security/pam_modules.h>
 #include <security/_pam_macros.h>