diff --git a/contracts/HubPool.sol b/contracts/HubPool.sol
index d84b1057b..83fc7475f 100644
--- a/contracts/HubPool.sol
+++ b/contracts/HubPool.sol
@@ -113,13 +113,13 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     mapping(uint256 => CrossChainContract) public crossChainContracts;
 
     // WETH contract for Ethereum.
-    WETH9 public weth;
+    WETH9 public immutable weth;
 
     // Helper factory to deploy new LP tokens for enabled L1 tokens
-    LpTokenFactoryInterface public lpTokenFactory;
+    LpTokenFactoryInterface public immutable lpTokenFactory;
 
     // Finder contract for this network.
-    FinderInterface public finder;
+    FinderInterface public immutable finder;
 
     // When root bundles are disputed a price request is enqueued with the DVM to resolve the resolution.
     bytes32 public identifier = "IS_ACROSS_V2_BUNDLE_VALID";
diff --git a/contracts/Optimism_SpokePool.sol b/contracts/Optimism_SpokePool.sol
index a38297964..41723cd2a 100644
--- a/contracts/Optimism_SpokePool.sol
+++ b/contracts/Optimism_SpokePool.sol
@@ -18,7 +18,7 @@ contract Optimism_SpokePool is CrossDomainEnabled, SpokePool {
     uint32 public l1Gas = 5_000_000;
 
     // ETH is an ERC20 on OVM.
-    address public l2Eth = address(Lib_PredeployAddresses.OVM_ETH);
+    address public immutable l2Eth = address(Lib_PredeployAddresses.OVM_ETH);
 
     // Stores alternative token bridges to use for L2 tokens that don't go over the standard bridge. This is needed
     // to support non-standard ERC20 tokens on Optimism, such as DIA and SNX which both use custom bridges.
diff --git a/contracts/SpokePool.sol b/contracts/SpokePool.sol
index 19a40dd8a..2c7a4b592 100644
--- a/contracts/SpokePool.sol
+++ b/contracts/SpokePool.sol
@@ -39,7 +39,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
 
     // Address of WETH contract for this network. If an origin token matches this, then the caller can optionally
     // instruct this contract to wrap ETH when depositing.
-    WETH9 public weth;
+    WETH9 public immutable weth;
 
     // Any deposit quote times greater than or less than this value to the current contract time is blocked. Forces
     // caller to use an approximately "current" realized fee. Defaults to 10 minutes.