diff --git a/library/PCUIF_Types.ttcn b/library/PCUIF_Types.ttcn
index b6a1bfa2c..6be45df24 100644
--- a/library/PCUIF_Types.ttcn
+++ b/library/PCUIF_Types.ttcn
@@ -111,7 +111,9 @@ type record PCUIF_data {
 type record PCUIF_data_cnf {
 	PCUIF_Sapi	sapi,
 	OCT4		msg_id
-} with { variant "" };
+} with {
+	variant (msg_id) "BYTEORDER(last)"
+};
 
 type record PCUIF_rts_req {
 	PCUIF_Sapi	sapi,