diff --git a/foundry.toml b/foundry.toml
index f09acafc..10e4a4a4 100644
--- a/foundry.toml
+++ b/foundry.toml
@@ -8,6 +8,7 @@ optimizer = true
 optimizer_runs = 1
 via_ir = true
 solc_version = '0.8.25'
+evm_version = 'cancun'
 fs_permissions = [{ access = "read", path = "./"}]
 remappings = ['ds-test/=lib/forge-std/lib/ds-test/src/',
               'forge-std/=lib/forge-std/src/',
@@ -25,4 +26,4 @@ auto_detect_remappings = false
 [fmt]
 number_underscore = 'thousands'
 line_length = 100
-# See more config options https://github.com/foundry-rs/foundry/tree/master/config
\ No newline at end of file
+# See more config options https://github.com/foundry-rs/foundry/tree/master/config
diff --git a/src/mocks/EspressoTEEVerifier.sol b/src/mocks/EspressoTEEVerifier.sol
index 3b0518c0..1ed915da 100644
--- a/src/mocks/EspressoTEEVerifier.sol
+++ b/src/mocks/EspressoTEEVerifier.sol
@@ -9,12 +9,29 @@ pragma solidity ^0.8.0;
  */
 
 contract EspressoTEEVerifierMock {
+    enum TeeType {
+        SGX
+    }
+    mapping(address => bool) public registeredSigner;
     constructor() {}
 
-    function verify(
-        bytes calldata rawQuote,
-        bytes32 reportDataHash
-    ) external view returns (bool success) {
-        return (true);
+    function verify(bytes calldata signature, bytes32 userDataHash) external {
+        return;
+    }
+
+    function registerSigner(
+        bytes calldata attestation,
+        bytes calldata data,
+        TeeType teeType
+    ) external {
+        // data length should be 20 bytes
+        require(data.length == 20, "Invalid data length");
+
+        address signer = address(uint160(bytes20(data[:20])));
+        registeredSigner[signer] = true;
+    }
+
+    function registeredSigners(address signer, TeeType teeType) external view returns (bool) {
+        return registeredSigner[signer];
     }
 }
diff --git a/test/foundry/Inbox.t.sol b/test/foundry/Inbox.t.sol
index 5ee001a7..ee80daa5 100644
--- a/test/foundry/Inbox.t.sol
+++ b/test/foundry/Inbox.t.sol
@@ -110,8 +110,8 @@ contract InboxTest is AbsInboxTest {
         uint256 userEthBalanceBefore = address(user).balance;
 
         // deposit too many eth shall fail
-        // TODO: Fix test
         // vm.prank(user);
+        // TODO: Fix this test
         // uint256 invalidDepositAmount = 300 ether;
         // vm.expectRevert();
         // ethInbox.depositEth{value: invalidDepositAmount}();