diff --git a/include/mtp3.hrl b/include/mtp3.hrl
index 53025a7..66575f5 100644
--- a/include/mtp3.hrl
+++ b/include/mtp3.hrl
@@ -15,6 +15,7 @@
 	network_ind,
 	service_ind,
 	routing_label,
+	m3ua_mp,		% Message Priority, only in M3UA based msg
 	payload
 	}).
 
diff --git a/src/m3ua_codec.erl b/src/m3ua_codec.erl
index 03ec923..4a2d10c 100644
--- a/src/m3ua_codec.erl
+++ b/src/m3ua_codec.erl
@@ -63,7 +63,7 @@ parse_m3ua_opt(Opt = ?M3UA_IEI_PROTOCOL_DATA, MsgBin) when is_binary(MsgBin) ->
 			routing_label = #mtp3_routing_label{sig_link_sel = Sls,
 							    origin_pc = Opc,
 							    dest_pc = Dpc},
-			payload = Payload}};
+			payload = Payload, m3ua_mp = Mp}};
 parse_m3ua_opt(Opt, Msg) ->
 	{Opt, Msg}.
 
@@ -89,8 +89,8 @@ encode_m3ua_opt(?M3UA_IEI_PROTOCOL_DATA, Mtp3) when is_record(Mtp3, mtp3_msg) ->
 		  routing_label = #mtp3_routing_label{sig_link_sel = Sls,
 						      origin_pc = Opc,
 						      dest_pc = Dpc},
-		  payload = Payload} = Mtp3,
-	PayBin = <<Opc:32/big, Dpc:32/big, Si:8, Ni:8, 0:8, Sls:8, Payload/binary>>,
+		  payload = Payload, m3ua_mp = Mp} = Mtp3,
+	PayBin = <<Opc:32/big, Dpc:32/big, Si:8, Ni:8, Mp:8, Sls:8, Payload/binary>>,
 	encode_m3ua_opt(?M3UA_IEI_PROTOCOL_DATA, PayBin);
 encode_m3ua_opt(Iei, Data) when is_integer(Iei), is_binary(Data) ->
 	Length = byte_size(Data) + 4,
diff --git a/test/mtp3_codec_tests.erl b/test/mtp3_codec_tests.erl
index f3d6a40..86e944c 100644
--- a/test/mtp3_codec_tests.erl
+++ b/test/mtp3_codec_tests.erl
@@ -6,7 +6,7 @@
 -include("mtp3.hrl").
 
 -define(MTP3_MSG_BIN, <<131,92,64,0,192,9,0,3,13,24,10,18,7,0,18,4,83,132,9,0,23,11,18,6,0,18,4,68,119,88,16,70,35,67,100,65,73,4,81,1,2,200,107,42,40,40,6,7,0,17,134,5,1,1,1,160,29,97,27,128,2,7,128,161,9,6,7,4,0,0,1,0,1,3,162,3,2,1,0,163,5,161,3,2,1,0,108,13,163,11,2,1,64,2,1,8,48,3,10,1,0>>).
--define(MTP3_MSG_DEC, {mtp3_msg,2,3,{mtp3_routing_label,5,12544,192},<<9,0,3,13,24,10,18,7,0,18,4,83,132,9,0,23,11,18,6,0,18,4,68,119,88,16,70,35,67,100,65,73,4,81,1,2,200,107,42,40,40,6,7,0,17,134,5,1,1,1,160,29,97,27,128,2,7,128,161,9,6,7,4,0,0,1,0,1,3,162,3,2,1,0,163,5,161,3,2,1,0,108,13,163,11,2,1,64,2,1,8,48,3,10,1,0>>}).
+-define(MTP3_MSG_DEC, {mtp3_msg,2,3,{mtp3_routing_label,5,12544,192},undefined,<<9,0,3,13,24,10,18,7,0,18,4,83,132,9,0,23,11,18,6,0,18,4,68,119,88,16,70,35,67,100,65,73,4,81,1,2,200,107,42,40,40,6,7,0,17,134,5,1,1,1,160,29,97,27,128,2,7,128,161,9,6,7,4,0,0,1,0,1,3,162,3,2,1,0,163,5,161,3,2,1,0,108,13,163,11,2,1,64,2,1,8,48,3,10,1,0>>}).
 
 parse_test() ->
 	?assertEqual(?MTP3_MSG_DEC, mtp3_codec:parse_mtp3_msg(?MTP3_MSG_BIN)).