diff --git a/lib/nitro-validator b/lib/nitro-validator
index 9a3626e..c86a250 160000
--- a/lib/nitro-validator
+++ b/lib/nitro-validator
@@ -1 +1 @@
-Subproject commit 9a3626e348a787e4c0d5f44b022c3656aa9a3fe7
+Subproject commit c86a250b0121c3fb4249a4e991df4d452e25cc05
diff --git a/script/DeploySystem.s.sol b/script/DeploySystem.s.sol
index cd61660..4f0d539 100644
--- a/script/DeploySystem.s.sol
+++ b/script/DeploySystem.s.sol
@@ -21,7 +21,7 @@ import {DeployChain} from "src/DeployChain.sol";
 import {Constants} from "@eth-optimism-bedrock/src/libraries/Constants.sol";
 import {ResourceMetering} from "@eth-optimism-bedrock/src/L1/ResourceMetering.sol";
 import {IResourceMetering} from "@eth-optimism-bedrock/src/L1/interfaces/IResourceMetering.sol";
-import {CertManager} from "@nitro-validator/CertManager.sol";
+import {ICertManager} from "@nitro-validator/ICertManager.sol";
 
 import {console2 as console} from "forge-std/console2.sol";
 
@@ -133,7 +133,7 @@ contract DeploySystem is Deploy {
 
         uint256 timestamp = vm.getBlockTimestamp();
         vm.warp(1732580000);
-        CertManager(certManagerAddress).verifyCert(cert, false, keccak256(parent));
+        ICertManager(certManagerAddress).verifyCert(cert, false, keccak256(parent));
         vm.warp(timestamp);
     }
 
@@ -157,7 +157,7 @@ contract DeploySystem is Deploy {
 
     function deploySystemConfigGlobal() public broadcast returns (address addr_) {
         console.log("Deploying SystemConfigGlobal implementation");
-        addr_ = address(new SystemConfigGlobal{salt: _implSalt()}(CertManager(mustGetAddress("CertManager"))));
+        addr_ = address(new SystemConfigGlobal{salt: _implSalt()}(ICertManager(mustGetAddress("CertManager"))));
         save("SystemConfigGlobal", addr_);
         console.log("SystemConfigGlobal deployed at %s", addr_);
     }
diff --git a/src/SystemConfigGlobal.sol b/src/SystemConfigGlobal.sol
index 918e25f..7fe5533 100644
--- a/src/SystemConfigGlobal.sol
+++ b/src/SystemConfigGlobal.sol
@@ -6,7 +6,7 @@ import {OwnableUpgradeable} from "@openzeppelin/contracts-upgradeable/access/Own
 import {ISemver} from "@eth-optimism-bedrock/src/universal/interfaces/ISemver.sol";
 import {NitroValidator} from "@nitro-validator/NitroValidator.sol";
 import {CborDecode} from "@nitro-validator/CborDecode.sol";
-import {CertManager} from "@nitro-validator/CertManager.sol";
+import {ICertManager} from "@nitro-validator/ICertManager.sol";
 
 contract SystemConfigGlobal is OwnableUpgradeable, ISemver, NitroValidator {
     using CborDecode for bytes;
@@ -28,7 +28,7 @@ contract SystemConfigGlobal is OwnableUpgradeable, ISemver, NitroValidator {
         return "0.0.1";
     }
 
-    constructor(CertManager certManager) NitroValidator(certManager) {
+    constructor(ICertManager certManager) NitroValidator(certManager) {
         initialize({_owner: address(0xdEaD)});
     }
 
diff --git a/test/SystemConfigGlobal.t.sol b/test/SystemConfigGlobal.t.sol
index 951229d..898f7b8 100644
--- a/test/SystemConfigGlobal.t.sol
+++ b/test/SystemConfigGlobal.t.sol
@@ -2,6 +2,7 @@
 pragma solidity ^0.8.15;
 
 import {Test, console} from "forge-std/Test.sol";
+import {CertManager} from "@nitro-validator/CertManager.sol";
 
 import "../src/SystemConfigGlobal.sol";