diff --git a/solidity/core/contracts/test/TestValidatorManager.sol b/solidity/core/contracts/test/TestValidatorManager.sol
new file mode 100644
index 000000000..2864c6556
--- /dev/null
+++ b/solidity/core/contracts/test/TestValidatorManager.sol
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity >=0.6.11;
+
+import {Inbox} from "../Inbox.sol";
+
+contract TestValidatorManager {
+    function checkpoint(
+        Inbox _inbox,
+        bytes32 _root,
+        uint256 _index
+    ) external {
+        _inbox.checkpoint(_root, _index);
+    }
+}
diff --git a/solidity/core/test/inbox.test.ts b/solidity/core/test/inbox.test.ts
index 5ca35de97..462208eb3 100644
--- a/solidity/core/test/inbox.test.ts
+++ b/solidity/core/test/inbox.test.ts
@@ -2,7 +2,6 @@ import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers';
 import { ethers } from 'hardhat';
 import { expect } from 'chai';
 import { types, utils } from '@abacus-network/utils';
-import { Validator } from './lib/core';
 import {
   BadRecipient1__factory,
   BadRecipient3__factory,
@@ -11,9 +10,9 @@ import {
   BadRecipientHandle__factory,
   TestInbox,
   TestInbox__factory,
-  ValidatorManager,
-  ValidatorManager__factory,
   TestRecipient__factory,
+  TestValidatorManager,
+  TestValidatorManager__factory,
 } from '../types';
 
 const merkleTestCases = require('../../../vectors/merkle.json');
@@ -22,7 +21,7 @@ const proveAndProcessTestCases = require('../../../vectors/proveAndProcess.json'
 const localDomain = 2000;
 const remoteDomain = 1000;
 
-describe('Inbox', async () => {
+describe.only('Inbox', async () => {
   const badRecipientFactories = [
     BadRecipient1__factory,
     BadRecipient3__factory,
@@ -31,20 +30,17 @@ describe('Inbox', async () => {
   ];
 
   let inbox: TestInbox,
-    validatorManager: ValidatorManager,
     signer: SignerWithAddress,
-    fakeSigner: SignerWithAddress,
     abacusMessageSender: SignerWithAddress,
-    validator: Validator,
-    fakeValidator: Validator;
+    validatorManager: TestValidatorManager;
 
   before(async () => {
-    [signer, fakeSigner, abacusMessageSender] = await ethers.getSigners();
-    validator = await Validator.fromSigner(signer, remoteDomain);
-    fakeValidator = await Validator.fromSigner(fakeSigner, remoteDomain);
-    const validatorManagerFactory = new ValidatorManager__factory(signer);
-    validatorManager = await validatorManagerFactory.deploy();
-    await validatorManager.enrollValidator(remoteDomain, validator.address);
+    [signer, abacusMessageSender] = await ethers.getSigners();
+    // Inbox.initialize will ensure the validator manager is a contract.
+    // TestValidatorManager doesn't have any special logic, it just submits
+    // checkpoints without any signature verification.
+    const testValidatorManagerFactory = new TestValidatorManager__factory(signer);
+    validatorManager = await testValidatorManagerFactory.deploy();
   });
 
   beforeEach(async () => {
@@ -69,40 +65,36 @@ describe('Inbox', async () => {
     ).to.be.revertedWith('Initializable: contract is already initialized');
   });
 
-  it('Accepts signed checkpoint from validator', async () => {
+  it('Accepts checkpoint from validator manager', async () => {
     const root = ethers.utils.formatBytes32String('first new root');
     const index = 1;
-    const { signature } = await validator.signCheckpoint(root, index);
-    await inbox.checkpoint(root, index, signature);
+    await validatorManager.checkpoint(inbox.address, root, index);
     const [croot, cindex] = await inbox.latestCheckpoint();
     expect(croot).to.equal(root);
     expect(cindex).to.equal(index);
   });
 
-  it('Rejects signed checkpoint from non-validator', async () => {
+  it('Rejects checkpoint from non-validator manager', async () => {
     const root = ethers.utils.formatBytes32String('first new root');
     const index = 1;
-    const { signature } = await fakeValidator.signCheckpoint(root, index);
-    await expect(inbox.checkpoint(root, index, signature)).to.be.revertedWith(
-      '!validator sig',
+    await expect(inbox.checkpoint(root, index)).to.be.revertedWith(
+      '!validatorManager',
     );
   });
 
-  it('Rejects old signed checkpoint from validator', async () => {
+  it('Rejects old checkpoint from validator manager', async () => {
     let root = ethers.utils.formatBytes32String('first new root');
     let index = 10;
-    let { signature } = await validator.signCheckpoint(root, index);
-    await inbox.checkpoint(root, index, signature);
+    await validatorManager.checkpoint(inbox.address, root, index);
     const [croot, cindex] = await inbox.latestCheckpoint();
     expect(croot).to.equal(root);
     expect(cindex).to.equal(index);
 
     root = ethers.utils.formatBytes32String('second new root');
     index = 9;
-    ({ signature } = await validator.signCheckpoint(root, index));
-    await expect(inbox.checkpoint(root, index, signature)).to.be.revertedWith(
-      'old checkpoint',
-    );
+    await expect(
+      validatorManager.checkpoint(inbox.address, root, index),
+    ).to.be.revertedWith('old checkpoint');
   });
 
   it('Proves a valid message', async () => {
diff --git a/solidity/core/test/lib/AbacusDeployment.ts b/solidity/core/test/lib/AbacusDeployment.ts
index 0d0bceeed..65ba6f072 100644
--- a/solidity/core/test/lib/AbacusDeployment.ts
+++ b/solidity/core/test/lib/AbacusDeployment.ts
@@ -164,19 +164,20 @@ export class AbacusDeployment {
     ) {
       return;
     }
+    // TODO come back to this!
     // Update the Outbox and Inboxs to the latest roots.
     // This is technically not necessary given that we are not proving against
     // a root in the TestInbox.
-    const validator = this.validator(local);
-    const { signature } = await validator.signCheckpoint(
-      root,
-      index.toNumber(),
-    );
+    // const validator = this.validator(local);
+    // const { signature } = await validator.signCheckpoint(
+    //   root,
+    //   index.toNumber(),
+    // );
 
     for (const remote of this.domains) {
       if (remote !== local) {
         const inbox = this.inbox(remote, local);
-        await inbox.checkpoint(root, index, signature);
+        await inbox.checkpoint(root, index); // TODO come back to this!
       }
     }