diff --git a/go/config/enclave_config.go b/go/config/enclave_config.go
index 9b201bfcfa..46ec99d326 100644
--- a/go/config/enclave_config.go
+++ b/go/config/enclave_config.go
@@ -73,7 +73,7 @@ func DefaultEnclaveConfig() *EnclaveConfig {
 		Address:                   "127.0.0.1:11000",
 		NodeType:                  common.Sequencer,
 		L1ChainID:                 1337,
-		ObscuroChainID:            777,
+		ObscuroChainID:            443,
 		WillAttest:                false, // todo (config) - attestation should be on by default before production release
 		ValidateL1Blocks:          false,
 		GenesisJSON:               nil,
diff --git a/go/config/host_config.go b/go/config/host_config.go
index 3783fce324..e8f8fdeb65 100644
--- a/go/config/host_config.go
+++ b/go/config/host_config.go
@@ -243,7 +243,7 @@ func DefaultHostParsedConfig() *HostInputConfig {
 		LogPath:                   "",
 		PrivateKeyString:          "0000000000000000000000000000000000000000000000000000000000000001",
 		L1ChainID:                 1337,
-		ObscuroChainID:            777,
+		ObscuroChainID:            443,
 		ProfilerEnabled:           false,
 		L1StartHash:               common.L1BlockHash{}, // this hash will not be found, host will log a warning and then stream from L1 genesis
 		SequencerID:               gethcommon.BytesToAddress([]byte("")),
diff --git a/integration/constants.go b/integration/constants.go
index f1ed44fa67..1e9f85ed83 100644
--- a/integration/constants.go
+++ b/integration/constants.go
@@ -31,5 +31,5 @@ const (
 
 const (
 	EthereumChainID = 1337
-	ObscuroChainID  = 777
+	ObscuroChainID  = 443
 )
diff --git a/integration/manualtests/tx_test.go b/integration/manualtests/tx_test.go
index f427ca980a..df9942f5b3 100644
--- a/integration/manualtests/tx_test.go
+++ b/integration/manualtests/tx_test.go
@@ -47,7 +47,7 @@ var (
 
 	l2Wallet = wallet.NewInMemoryWalletFromConfig(
 		"4bfe14725e685901c062ccd4e220c61cf9c189897b6c78bd18d7f51291b2b8f8",
-		777,
+		443,
 		gethlog.New())
 	l2Host = "localhost"
 	l2Port = 37900
diff --git a/tools/faucet/cmd/cli.go b/tools/faucet/cmd/cli.go
index f6bf8c4c3f..c5755c6fd8 100644
--- a/tools/faucet/cmd/cli.go
+++ b/tools/faucet/cmd/cli.go
@@ -50,6 +50,6 @@ func parseCLIArgs() *faucet.Config {
 		PK:         *faucetPK,
 		JWTSecret:  *jwtSecret,
 		ServerPort: *serverPort,
-		ChainID:    big.NewInt(777), // TODO make this configurable
+		ChainID:    big.NewInt(443), // TODO make this configurable
 	}
 }
diff --git a/tools/hardhatdeployer/cli.go b/tools/hardhatdeployer/cli.go
index c0d6b78911..3def80f0f2 100644
--- a/tools/hardhatdeployer/cli.go
+++ b/tools/hardhatdeployer/cli.go
@@ -14,7 +14,7 @@ const (
 
 var (
 	defaultL1ChainID = big.NewInt(1337)
-	defaultL2ChainID = big.NewInt(777)
+	defaultL2ChainID = big.NewInt(443)
 )
 
 // DefaultConfig stores the contract client default config
diff --git a/tools/hardhatdeployer/cli_flags.go b/tools/hardhatdeployer/cli_flags.go
index db12ffabb8..ef2395a697 100644
--- a/tools/hardhatdeployer/cli_flags.go
+++ b/tools/hardhatdeployer/cli_flags.go
@@ -18,7 +18,7 @@ const (
 	privateKeyUsage = "The private key for the node account"
 
 	chainIDName  = "chainID"
-	chainIDUsage = "The ID of the chain (defaults to 777 for L2 deployment and 1337 for L1)"
+	chainIDUsage = "The ID of the chain (defaults to 443 for L2 deployment and 1337 for L1)"
 
 	constructorParamsName  = "constructorParams"
 	constructorParamsUsage = "A comma separated list of strings that will be passed to the deployer. Defaults to empty."