diff --git a/src/gsm/apn.c b/src/gsm/apn.c
index ccf36b9..8d4b2bf 100644
--- a/src/gsm/apn.c
+++ b/src/gsm/apn.c
@@ -1,3 +1,5 @@
+/*! \file apn.c */
+
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>