diff --git a/.gitignore b/.gitignore
index e92090f4db..a1b1cc1f15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,7 @@ yarn-error.log
 !.yarn/plugins
 .pnp.*
 .node-version
+.go-version
 
 dist
 artifacts
diff --git a/op-bindings/predeploys/addresses.go b/op-bindings/predeploys/addresses.go
index 8dee1d6ab2..b337098b72 100644
--- a/op-bindings/predeploys/addresses.go
+++ b/op-bindings/predeploys/addresses.go
@@ -18,7 +18,7 @@ const (
 	L1Block                       = "0x4200000000000000000000000000000000000015"
 	GovernanceToken               = "0x4200000000000000000000000000000000000042"
 	LegacyMessagePasser           = "0x4200000000000000000000000000000000000000"
-	L2ERC721Bridge                = "0x4200000000000000000000000000000000000014"
+	OPStackL2ERC721Bridge         = "0x4200000000000000000000000000000000000014" // Reserved(but do not use)
 	OptimismMintableERC721Factory = "0x4200000000000000000000000000000000000017"
 	ProxyAdmin                    = "0x4200000000000000000000000000000000000018"
 	BaseFeeVault                  = "0x4200000000000000000000000000000000000019"
@@ -26,6 +26,9 @@ const (
 	SchemaRegistry                = "0x4200000000000000000000000000000000000020"
 	EAS                           = "0x4200000000000000000000000000000000000021"
 	Create2Deployer               = "0x13b0D85CcB8bf860b6b79AF3029fCA081AE9beF2"
+
+	// Oasys' L2 ERC721 Bridge was released before OPStack and has a different address.
+	OasysL2ERC721Bridge = "0x6200000000000000000000000000000000000001"
 )
 
 var (
@@ -41,7 +44,9 @@ var (
 	L1BlockAddr                       = common.HexToAddress(L1Block)
 	GovernanceTokenAddr               = common.HexToAddress(GovernanceToken)
 	LegacyMessagePasserAddr           = common.HexToAddress(LegacyMessagePasser)
-	L2ERC721BridgeAddr                = common.HexToAddress(L2ERC721Bridge)
+	L2ERC721BridgeAddr                = common.HexToAddress(OasysL2ERC721Bridge)
+	OPStackL2ERC721BridgeAddr         = common.HexToAddress(OPStackL2ERC721Bridge)
+	OasysL2ERC721BridgeAddr           = common.HexToAddress(OasysL2ERC721Bridge)
 	OptimismMintableERC721FactoryAddr = common.HexToAddress(OptimismMintableERC721Factory)
 	ProxyAdminAddr                    = common.HexToAddress(ProxyAdmin)
 	BaseFeeVaultAddr                  = common.HexToAddress(BaseFeeVault)
diff --git a/op-chain-ops/genesis/helpers.go b/op-chain-ops/genesis/helpers.go
index 475b597ccc..66b1bfd059 100644
--- a/op-chain-ops/genesis/helpers.go
+++ b/op-chain-ops/genesis/helpers.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/ethereum-optimism/optimism/op-bindings/predeploys"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
@@ -26,6 +27,12 @@ var (
 	ImplementationSlot = common.HexToHash("0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc")
 	// AdminSlot represents the EIP 1967 admin storage slot
 	AdminSlot = common.HexToHash("0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103")
+
+	// Namespace for L2 predeploy contracts made by Oasys.
+	oasysCodeNamespace           = common.HexToAddress("0xC0F6C0f6C0F6C0f6C0f6c0F6C0f6C0F6c0f60000")
+	bigOasysCodeNamespace        = new(big.Int).SetBytes(oasysCodeNamespace.Bytes())
+	oasysL2PredeployNamespace    = common.HexToAddress("0x6200000000000000000000000000000000000000")
+	OasysBigL2PredeployNamespace = new(big.Int).SetBytes(oasysL2PredeployNamespace.Bytes())
 )
 
 // DevAccounts represent the standard hardhat development accounts.
@@ -65,11 +72,15 @@ var devBalance = hexutil.MustDecodeBig("0x20000000000000000000000000000000000000
 // AddressToCodeNamespace takes a predeploy address and computes
 // the implementation address that the implementation should be deployed at
 func AddressToCodeNamespace(addr common.Address) (common.Address, error) {
-	if !IsL2DevPredeploy(addr) {
+	if addr == predeploys.OPStackL2ERC721BridgeAddr {
+		return common.Address{}, fmt.Errorf("do not use the OPStack's L2ERC721Bridge")
+	}
+	namespace := getCodeNamespace(addr)
+	if namespace == nil {
 		return common.Address{}, fmt.Errorf("cannot handle non predeploy: %s", addr)
 	}
 	bigAddress := new(big.Int).SetBytes(addr[18:])
-	num := new(big.Int).Or(bigCodeNamespace, bigAddress)
+	num := new(big.Int).Or(namespace, bigAddress)
 	return common.BigToAddress(num), nil
 }
 
@@ -107,3 +118,13 @@ func newHexBig(in uint64) *hexutil.Big {
 	hb := hexutil.Big(*b)
 	return &hb
 }
+
+func getCodeNamespace(addr common.Address) *big.Int {
+	if bytes.Equal(addr[0:2], []byte{0x42, 0x00}) {
+		return bigCodeNamespace
+	}
+	if bytes.Equal(addr[0:2], []byte{0x62, 0x00}) {
+		return bigOasysCodeNamespace
+	}
+	return nil
+}
diff --git a/op-chain-ops/genesis/layer_two.go b/op-chain-ops/genesis/layer_two.go
index 236dc16de8..1ff9330377 100644
--- a/op-chain-ops/genesis/layer_two.go
+++ b/op-chain-ops/genesis/layer_two.go
@@ -43,6 +43,10 @@ func BuildL2Genesis(config *DeployConfig, l1StartBlock *types.Block) (*core.Gene
 	if err != nil {
 		return nil, err
 	}
+	err = setProxies(db, predeploys.ProxyAdminAddr, OasysBigL2PredeployNamespace, 256)
+	if err != nil {
+		return nil, err
+	}
 
 	// Set up the implementations
 	deployResults, err := immutables.BuildOptimism(immutable)
diff --git a/op-chain-ops/genesis/layer_two_test.go b/op-chain-ops/genesis/layer_two_test.go
index dfa3e3fde4..391ee3fd04 100644
--- a/op-chain-ops/genesis/layer_two_test.go
+++ b/op-chain-ops/genesis/layer_two_test.go
@@ -91,7 +91,12 @@ func TestBuildL2MainnetGenesis(t *testing.T) {
 	config.EnableGovernance = true
 	config.FundDevAccounts = false
 	gen := testBuildL2Genesis(t, config)
-	require.Equal(t, 2323, len(gen.Alloc))
+	expect :=
+		256 + // `SetPrecompileBalances()`
+			2048 + // `setProxies()` with BigL2PredeployNamespace
+			256 + // `setProxies()` with OasysBigL2PredeployNamespace
+			20 // Implementations
+	require.Equal(t, expect, len(gen.Alloc))
 }
 
 func TestBuildL2MainnetNoGovernanceGenesis(t *testing.T) {
@@ -100,5 +105,10 @@ func TestBuildL2MainnetNoGovernanceGenesis(t *testing.T) {
 	config.EnableGovernance = false
 	config.FundDevAccounts = false
 	gen := testBuildL2Genesis(t, config)
-	require.Equal(t, 2323, len(gen.Alloc))
+	expect :=
+		256 + // `SetPrecompileBalances()`
+			2048 + // `setProxies()` with BigL2PredeployNamespace
+			256 + // `setProxies()` with OasysBigL2PredeployNamespace
+			20 // Implementations
+	require.Equal(t, expect, len(gen.Alloc))
 }