diff --git a/modules/access/mms/mmstu.c b/modules/access/mms/mmstu.c
index b1d73985c3..6cb7d1f8dc 100644
--- a/modules/access/mms/mmstu.c
+++ b/modules/access/mms/mmstu.c
@@ -1238,7 +1238,7 @@ static int  mms_ParseCommand( stream_t *p_access,
 }
 
 static int  mms_ParsePacket( stream_t *p_access,
-                             uint8_t *p_data, size_t i_data,
+                             const uint8_t *p_data, size_t i_data,
                              size_t *pi_used )
 {
     access_sys_t        *p_sys = p_access->p_sys;