--- a/src/sync.c	Wed Sep 16 15:13:51 2009 +0200
+++ b/src/sync.c	Wed Sep 16 15:15:28 2009 +0200
@@ -131,7 +131,7 @@
   
   MSG_WAR(0x3001, "sendSYNC ", 0);
   
-  m.cob_id = UNS16_LE(*d->COB_ID_Sync);
+  m.cob_id = (UNS16)UNS16_LE(*d->COB_ID_Sync);
   m.rtr = NOT_A_REQUEST;
   m.len = 0;