diff --git a/packages/protocol/contracts/L1/TaikoL1.sol b/packages/protocol/contracts/L1/TaikoL1.sol
index bb1b3579e5..685ca32d3e 100644
--- a/packages/protocol/contracts/L1/TaikoL1.sol
+++ b/packages/protocol/contracts/L1/TaikoL1.sol
@@ -202,7 +202,7 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
         // - anchorGasLimit: 250_000 (based on internal devnet, its ~220_000
         // after 256 L2 blocks)
         return TaikoData.Config({
-            chainId: 167_009,
+            chainId: LibNetwork.TAIKO,
             // Assume the block time is 3s, the protocol will allow ~90 days of
             // new blocks without any verification.
             blockMaxProposals: 3_000_000,
diff --git a/packages/protocol/contracts/libs/LibNetwork.sol b/packages/protocol/contracts/libs/LibNetwork.sol
index 24d7076252..46c3a18c9e 100644
--- a/packages/protocol/contracts/libs/LibNetwork.sol
+++ b/packages/protocol/contracts/libs/LibNetwork.sol
@@ -11,6 +11,8 @@ library LibNetwork {
     uint256 internal constant HOLESKY = 17_000;
     uint256 internal constant SEPOLIA = 11_155_111;
 
+    uint64 internal constant TAIKO = 167_000;
+
     /// @dev Checks if the chain ID represents an Ethereum testnet.
     /// @param _chainId The chain ID.
     /// @return true if the chain ID represents an Ethereum testnet, false otherwise.
@@ -28,6 +30,13 @@ library LibNetwork {
         return _chainId == LibNetwork.MAINNET || isEthereumTestnet(_chainId);
     }
 
+    /// @dev Checks if the chain ID represents the Taiko L2 mainnet.
+    /// @param _chainId The chain ID.
+    /// @return true if the chain ID represents the Taiko L2 mainnet.
+    function isTaikoMainnet(uint256 _chainId) internal pure returns (bool) {
+        return _chainId == TAIKO;
+    }
+
     /// @dev Checks if the chain ID represents an internal Taiko devnet's base layer.
     /// @param _chainId The chain ID.
     /// @return true if the chain ID represents an internal Taiko devnet's base layer, false