diff --git a/library/RLCMAC_Types.ttcn b/library/RLCMAC_Types.ttcn
index eb9d845..3110a66 100644
--- a/library/RLCMAC_Types.ttcn
+++ b/library/RLCMAC_Types.ttcn
@@ -115,6 +115,11 @@
 		DlCtrlOptOctets		opt optional,
 		RlcmacDlCtrlMsg		payload
 	} with {
+		/* Automatic padding by RAW encoder seems to causing problems
+		 * due to padding sequence 2b inserted shifted from octet
+		 * boundary on some messags. See UL CTRL blocks in TC_t3193.
+		 * See 3GPP TS 44.060 Figure 11.1 (below)
+		 * variant "PADDING(184), PADDING_PATTERN('00101011'B)" */
 		variant (opt) "PRESENCE(mac_hdr.payload_type = MAC_PT_RLCMAC_OPT)"
 	};
 
@@ -133,7 +138,14 @@
 	type record RlcmacUlCtrlBlock {
 		UlMacCtrlHeader		mac_hdr,
 		RlcmacUlCtrlMsg		payload
-	} with { variant "" };
+	} with {
+		/* Automatic padding by RAW encoder seems to causing problems
+		 * due to padding sequence 2b inserted shifted from octet
+		 * boundary on some messags. See UL CTRL blocks in TC_t3193.
+		 * See 3GPP TS 44.060 Figure 11.1 (below)
+		 * variant "PADDING(184), PADDING_PATTERN('00101011'B)" */
+		 variant ""
+		};
 
 	external function enc_RlcmacUlCtrlBlock(in RlcmacUlCtrlBlock si) return octetstring
 		with { extension "prototype(convert) encode(RAW)" };