diff --git a/contracts/test/TestGuardableModifier.sol b/contracts/test/TestGuardableModifier.sol
new file mode 100644
index 00000000..98333afd
--- /dev/null
+++ b/contracts/test/TestGuardableModifier.sol
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity >=0.7.0 <0.9.0;
+
+import "../core/GuardableModifier.sol";
+
+contract TestGuardableModifier is GuardableModifier {
+    event executed(
+        address to,
+        uint256 value,
+        bytes data,
+        Enum.Operation operation,
+        bool success
+    );
+
+    event executedAndReturnedData(
+        address to,
+        uint256 value,
+        bytes data,
+        Enum.Operation operation,
+        bytes returnData,
+        bool success
+    );
+
+    constructor(address _avatar, address _target) {
+        bytes memory initParams = abi.encode(_avatar, _target);
+        setUp(initParams);
+    }
+
+    /// @dev Passes a transaction to the modifier.
+    /// @param to Destination address of module transaction
+    /// @param value Ether value of module transaction
+    /// @param data Data payload of module transaction
+    /// @param operation Operation type of module transaction
+    /// @notice Can only be called by enabled modules
+    function execTransactionFromModule(
+        address to,
+        uint256 value,
+        bytes calldata data,
+        Enum.Operation operation
+    ) public override moduleOnly returns (bool success) {
+        success = exec(to, value, data, operation);
+        emit executed(to, value, data, operation, success);
+    }
+
+    /// @dev Passes a transaction to the modifier, expects return data.
+    /// @param to Destination address of module transaction
+    /// @param value Ether value of module transaction
+    /// @param data Data payload of module transaction
+    /// @param operation Operation type of module transaction
+    /// @notice Can only be called by enabled modules
+    function execTransactionFromModuleReturnData(
+        address to,
+        uint256 value,
+        bytes calldata data,
+        Enum.Operation operation
+    )
+        public
+        override
+        moduleOnly
+        returns (bool success, bytes memory returnData)
+    {
+        (success, returnData) = execAndReturnData(to, value, data, operation);
+        emit executedAndReturnedData(
+            to,
+            value,
+            data,
+            operation,
+            returnData,
+            success
+        );
+    }
+
+    function setUp(bytes memory initializeParams) public override initializer {
+        setupModules();
+        __Ownable_init();
+        (address _avatar, address _target) = abi.decode(
+            initializeParams,
+            (address, address)
+        );
+        avatar = _avatar;
+        target = _target;
+    }
+
+    function attemptToSetupModules() public {
+        setupModules();
+    }
+}
diff --git a/test/07_GuardableModifier.spec.ts b/test/07_GuardableModifier.spec.ts
new file mode 100644
index 00000000..723b64d3
--- /dev/null
+++ b/test/07_GuardableModifier.spec.ts
@@ -0,0 +1,180 @@
+import hre from "hardhat";
+import { expect } from "chai";
+import { loadFixture } from "@nomicfoundation/hardhat-network-helpers";
+
+import {
+  TestAvatar__factory,
+  TestGuard__factory,
+  TestGuardableModifier__factory,
+} from "../typechain-types";
+
+describe("GuardableModifier", async () => {
+  async function setupTests() {
+    const [signer, someone, executor] = await hre.ethers.getSigners();
+
+    const Avatar = await hre.ethers.getContractFactory("TestAvatar");
+    const avatar = TestAvatar__factory.connect(
+      (await Avatar.deploy()).address,
+      signer
+    );
+
+    const Modifier = await hre.ethers.getContractFactory(
+      "TestGuardableModifier"
+    );
+    const modifier = TestGuardableModifier__factory.connect(
+      (await Modifier.connect(signer).deploy(avatar.address, avatar.address))
+        .address,
+      signer
+    );
+    const Guard = await hre.ethers.getContractFactory("TestGuard");
+    const guard = TestGuard__factory.connect(
+      (await Guard.deploy(modifier.address)).address,
+      hre.ethers.provider
+    );
+
+    await avatar.enableModule(modifier.address);
+    await modifier.enableModule(executor.address);
+
+    return {
+      avatar,
+      someone,
+      executor,
+      guard,
+      modifier,
+    };
+  }
+
+  describe("exec", async () => {
+    it("skips guard pre-check if no guard is set", async () => {
+      const { avatar, modifier, executor } = await loadFixture(setupTests);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModule(avatar.address, 0, "0x", 0)
+      ).to.not.be.reverted;
+    });
+
+    it("pre-checks transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModule(avatar.address, 0, "0x", 0)
+      )
+        .to.emit(guard, "PreChecked")
+        .withArgs(true);
+    });
+
+    it("pre-checks and reverts transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModule(avatar.address, 1337, "0x", 0)
+      ).to.be.revertedWith("Cannot send 1337");
+    });
+
+    it("skips post-check if no guard is enabled", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModule(avatar.address, 0, "0x", 0)
+      ).not.to.emit(guard, "PostChecked");
+    });
+
+    it("post-checks transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModule(avatar.address, 0, "0x", 0)
+      )
+        .to.emit(guard, "PostChecked")
+        .withArgs(true);
+    });
+  });
+
+  describe("execAndReturnData", async () => {
+    it("skips guard pre-check if no guard is set", async () => {
+      const { avatar, modifier, executor } = await loadFixture(setupTests);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModuleReturnData(avatar.address, 0, "0x", 0)
+      ).to.not.be.reverted;
+    });
+
+    it("pre-checks transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModuleReturnData(avatar.address, 0, "0x", 0)
+      )
+        .to.emit(guard, "PreChecked")
+        .withArgs(true);
+    });
+
+    it("pre-checks and reverts transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModuleReturnData(avatar.address, 1337, "0x", 0)
+      ).to.be.revertedWith("Cannot send 1337");
+    });
+
+    it("skips post-check if no guard is enabled", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModuleReturnData(avatar.address, 0, "0x", 0)
+      ).not.to.emit(guard, "PostChecked");
+    });
+
+    it("post-checks transaction if guard is set", async () => {
+      const { avatar, executor, modifier, guard } = await loadFixture(
+        setupTests
+      );
+      await modifier.setGuard(guard.address);
+
+      await expect(
+        modifier
+          .connect(executor)
+          .execTransactionFromModuleReturnData(avatar.address, 0, "0x", 0)
+      )
+        .to.emit(guard, "PostChecked")
+        .withArgs(true);
+    });
+  });
+});