diff --git a/library/GSM_RR_Types.ttcn b/library/GSM_RR_Types.ttcn
index 4b460b1..d0d5d8e 100644
--- a/library/GSM_RR_Types.ttcn
+++ b/library/GSM_RR_Types.ttcn
@@ -186,6 +186,18 @@
 		uint6_t		hsn
 	} with { variant "" };
 
+	/* It's more handy to pass HSN first, so the arguments' order is reversed. */
+	template (value) MaioHsn ts_HsnMaio(template (value) uint6_t hsn,
+					    template (value) uint6_t maio) := {
+		maio := maio,
+		hsn := hsn
+	};
+	template MaioHsn tr_HsnMaio(template (present) uint6_t hsn,
+				    template (present) uint6_t maio) := {
+		maio := maio,
+		hsn := hsn
+	};
+
 	/* TS 24.008 10.5.1.1 */
 	type uint16_t CellIdentity;