diff --git a/channels/chan_misdn.c b/channels/chan_misdn.c
index 9a532230a6..38a2151f8e 100644
--- a/channels/chan_misdn.c
+++ b/channels/chan_misdn.c
@@ -21,8 +21,11 @@
  * \file
  *
  * \brief the chan_misdn channel driver for Asterisk
+ *
  * \author Christian Richter <crich@beronet.com>
  *
+ * \extref MISDN http://www.misdn.org/
+ *
  * \ingroup channel_drivers
  */