diff --git a/relayer/message/message.go b/relayer/message/message.go
index 677318bf..a1c2fc82 100644
--- a/relayer/message/message.go
+++ b/relayer/message/message.go
@@ -12,8 +12,8 @@ const (
 
 type MessageType string
 type Message struct {
-	Source      uint8       // Source where message was initiated
-	Destination uint8       // Destination chain of message
+	Source      uint64      // Source where message was initiated
+	Destination uint64      // Destination chain of message
 	Data        interface{} // Data associated with the message
 	ID          string      // ID is used to track and identify message across networks
 	Type        MessageType // Message type
@@ -21,7 +21,7 @@ type Message struct {
 }
 
 func NewMessage(
-	source, destination uint8,
+	source, destination uint64,
 	data interface{},
 	id string,
 	msgType MessageType,
diff --git a/relayer/relayer.go b/relayer/relayer.go
index b9f75e5d..702eafda 100644
--- a/relayer/relayer.go
+++ b/relayer/relayer.go
@@ -27,7 +27,7 @@ type MessageTracker interface {
 	TrackMessages(msgs []*message.Message, status message.MessageStatus)
 }
 
-func NewRelayer(chains map[uint8]RelayedChain, messageTracker MessageTracker) *Relayer {
+func NewRelayer(chains map[uint64]RelayedChain, messageTracker MessageTracker) *Relayer {
 	return &Relayer{
 		relayedChains:  chains,
 		messageTracker: messageTracker,
@@ -35,7 +35,7 @@ func NewRelayer(chains map[uint8]RelayedChain, messageTracker MessageTracker) *R
 }
 
 type Relayer struct {
-	relayedChains  map[uint8]RelayedChain
+	relayedChains  map[uint64]RelayedChain
 	messageTracker MessageTracker
 }
 
@@ -66,7 +66,7 @@ func (r *Relayer) route(msgs []*message.Message) {
 	r.messageTracker.TrackMessages(msgs, message.PendingMessage)
 	destChain, ok := r.relayedChains[msgs[0].Destination]
 	if !ok {
-		log.Error().Uint8("domainID", msgs[0].Destination).Msgf("No chain registered for destination domain")
+		log.Error().Uint64("domainID", msgs[0].Destination).Msgf("No chain registered for destination domain")
 		return
 	}
 
diff --git a/relayer/relayer_test.go b/relayer/relayer_test.go
index ff0bf9d0..ed979905 100644
--- a/relayer/relayer_test.go
+++ b/relayer/relayer_test.go
@@ -43,7 +43,7 @@ func (s *RouteTestSuite) TestStartListensOnChannel() {
 		return 1
 	})
 	s.mockRelayedChain.EXPECT().ReceiveMessage(gomock.Any()).Return(nil, fmt.Errorf("error"))
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,
@@ -61,7 +61,7 @@ func (s *RouteTestSuite) TestStartListensOnChannel() {
 func (s *RouteTestSuite) TestReceiveMessageFails() {
 	s.mockRelayedChain.EXPECT().DomainID().Return(uint8(1)).Times(1)
 	s.mockRelayedChain.EXPECT().ReceiveMessage(gomock.Any()).Return(nil, fmt.Errorf("error"))
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,
@@ -76,7 +76,7 @@ func (s *RouteTestSuite) TestReceiveMessageFails() {
 func (s *RouteTestSuite) TestAvoidWriteWithoutProposals() {
 	s.mockRelayedChain.EXPECT().ReceiveMessage(gomock.Any()).Return(nil, nil)
 	s.mockRelayedChain.EXPECT().DomainID().Return(uint8(1))
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,
@@ -95,7 +95,7 @@ func (s *RouteTestSuite) TestWriteFails() {
 	s.mockRelayedChain.EXPECT().ReceiveMessage(gomock.Any()).Return(prop, nil)
 	s.mockRelayedChain.EXPECT().Write(props).Return(fmt.Errorf("error"))
 	s.mockRelayedChain.EXPECT().DomainID().Return(uint8(1)).Times(1)
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,
@@ -114,7 +114,7 @@ func (s *RouteTestSuite) TestWritesToChain() {
 	s.mockRelayedChain.EXPECT().ReceiveMessage(gomock.Any()).Return(prop, nil)
 	s.mockRelayedChain.EXPECT().Write(props).Return(nil)
 	s.mockRelayedChain.EXPECT().DomainID().Return(uint8(1)).Times(1)
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,
@@ -130,7 +130,7 @@ func (s *RouteTestSuite) Test_Route_ChainDoesNotExist() {
 	props := make([]*proposal.Proposal, 1)
 	prop := &proposal.Proposal{}
 	props[0] = prop
-	chains := make(map[uint8]RelayedChain)
+	chains := make(map[uint64]RelayedChain)
 	chains[1] = s.mockRelayedChain
 	relayer := NewRelayer(
 		chains,