diff --git a/library/RLCMAC_CSN1_Types.ttcn b/library/RLCMAC_CSN1_Types.ttcn
index 6bdca40..cc1ae22 100644
--- a/library/RLCMAC_CSN1_Types.ttcn
+++ b/library/RLCMAC_CSN1_Types.ttcn
@@ -807,13 +807,13 @@
 		RflNumberList		rfl_number_list optional,
 		BIT1			ma_present,
 		uint6_t			ma_length optional,
-		bitstring		ma_bitmap optional
+		bitstring		ma_bitmap length(1..64) optional
 		/* TODO: ARFCN index list */
 	} with {
 		variant (rfl_number_list) "PRESENCE(rfl_number_list_present = '1'B)"
 		variant (ma_length) "PRESENCE(ma_present = '0'B)"
 		variant (ma_bitmap) "PRESENCE(ma_present = '0'B)"
-		variant (ma_length) "LENGTHTO(ma_bitmap)+1"
+		variant (ma_length) "LENGTHTO(ma_bitmap)-1, UNIT(bits)"
 		variant (ma_bitmap) "BYTEORDER(first), BITORDER(msb)"
 	};