diff --git a/library/RLCMAC_CSN1_Types.ttcn b/library/RLCMAC_CSN1_Types.ttcn
index 11df29d..321049c 100644
--- a/library/RLCMAC_CSN1_Types.ttcn
+++ b/library/RLCMAC_CSN1_Types.ttcn
@@ -230,6 +230,8 @@
 	type union PageInfo {
 		PageInfoPs		ps,
 		PageInfoCs		cs
+	} with {
+		variant "TAG(ps, presence = '0'B; cs, presence = '1'B)"
 	};
 	type record PacketPagingReq {
 		PageMode		page_mode,