diff --git a/library/GSM_Types.ttcn b/library/GSM_Types.ttcn
index a08edb2d1..a99223516 100644
--- a/library/GSM_Types.ttcn
+++ b/library/GSM_Types.ttcn
@@ -496,22 +496,22 @@ module GSM_Types {
 		RSL_CHAN_NR_BCCH	('10'H),
 		RSL_CHAN_NR_RACH	('11'H),
 		RSL_CHAN_NR_PCH_AGCH	('12'H)
-	} with { variant "FIELDLENGTH(5)" };
+	} with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" };
 
 	type record RslChanNr2 {
 		BIT4		tag ('0001'B),
 		uint1_t		sub_chan
-	} with { variant "FIELDLENGTH(5)" };
+	} with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" };
 
 	type record RslChanNr4 {
 		BIT3		tag ('001'B),
 		uint2_t		sub_chan
-	} with { variant "FIELDLENGTH(5)" };
+	} with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" };
 
 	type record RslChanNr8 {
 		BIT2		tag ('01'B),
 		uint3_t		sub_chan
-	} with { variant "FIELDLENGTH(5)" };
+	} with { variant "FIELDLENGTH(5)" variant "FIELDORDER(msb)" };
 
 	type union RslChanNrU {
 		RslChanNr0	ch0,
@@ -524,12 +524,13 @@ module GSM_Types {
 			     sdcch8, tag = '01'B;
 			     ch0, OTHERWISE)"
 		variant "FIELDLENGTH(5)"
+		variant "FIELDORDER(msb)"
 	};
 
 	type record RslChannelNr {
 		RslChanNrU	u,
 		uint3_t		tn
-	} with { variant "FIELDLENGTH(8)" };
+	} with { variant "FIELDLENGTH(8)" variant "FIELDORDER(msb)" };
 
 	template RslChannelNr t_RslChanNr0(template uint3_t tn, template RslChanNr0 cht) := {
 		u := { ch0 := cht },