diff --git a/src/contracts/mixins/SignatureUtils.sol b/src/contracts/mixins/SignatureUtils.sol
index 79a5e932a..18f9c8984 100644
--- a/src/contracts/mixins/SignatureUtils.sol
+++ b/src/contracts/mixins/SignatureUtils.sol
@@ -40,19 +40,21 @@ abstract contract SignatureUtils is ISignatureUtils {
      * for more detailed information please read EIP-712.
      * @dev Use `_calculateDomainSeparator` rather than using this function.
      */
-    function domainSeparator() external view virtual returns (bytes32) {
-        return _calculateDomainSeparator();
+    function domainSeparator() public view virtual returns (bytes32) {
+        /// forgefmt: disable-next-item
+        return block.chainid == _INITIAL_CHAIN_ID
+            // If the chain ID is the same, return the original domain separator.
+            ? _INITIAL_DOMAIN_SEPARATOR
+            // If the chain ID is different, return the new domain separator.
+            : _calculateDomainSeparator();
     }
 
     /// INTERNAL HELPERS
 
-    /// @dev Helper for calculating the contract's current domain separator.
+    /// @dev Helper for calculating the contract's domain separator.
     function _calculateDomainSeparator() internal view returns (bytes32) {
         /// forgefmt: disable-next-item
-        return block.chainid == _INITIAL_CHAIN_ID ?
-            // If the chain ID is the same, return the original domain separator.
-            _INITIAL_DOMAIN_SEPARATOR :
-            // If the chain ID is different, return the new domain separator.
+        return 
             keccak256(
                 abi.encode(
                     EIP712_DOMAIN_TYPEHASH, 
@@ -67,7 +69,7 @@ abstract contract SignatureUtils is ISignatureUtils {
     function _calculateSignableDigest(
         bytes32 hash
     ) internal view returns (bytes32) {
-        return keccak256(abi.encodePacked("\x19\x01", _calculateDomainSeparator(), hash));
+        return keccak256(abi.encodePacked("\x19\x01", domainSeparator(), hash));
     }
 
     /// @dev Helper for checking if a signature is valid, reverts if not valid.
diff --git a/src/test/unit/mixins/SignatureUtilsUnit.t.sol b/src/test/unit/mixins/SignatureUtilsUnit.t.sol
new file mode 100644
index 000000000..b6dffecfd
--- /dev/null
+++ b/src/test/unit/mixins/SignatureUtilsUnit.t.sol
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.27;
+
+import "forge-std/Test.sol";
+import "src/contracts/mixins/SignatureUtils.sol";
+
+contract MockSigner {
+    mapping(bytes32 => mapping(bytes => bool)) public validSignatures;
+
+    function setValidSignature(bytes32 digest, bytes memory signature, bool valid) public {
+        validSignatures[digest][signature] = valid;
+    }
+
+    function isValidSignatureNow(bytes32 digest, bytes memory signature) public view returns (bool) {
+        return validSignatures[digest][signature];
+    }
+}
+
+contract SignatureUtilsUnit is Test, SignatureUtils {
+    uint256 signerPk;
+    address signer;
+    bytes32 hash;
+    bytes32 digest;
+    bytes32 expectedDomainSeparator;
+
+    function setUp() public {
+        vm.chainId(1);
+
+        signerPk = 1;
+        signer = vm.addr(signerPk);
+        
+        hash = keccak256("");
+        digest = _calculateSignableDigest(hash);
+
+        expectedDomainSeparator = keccak256(
+            abi.encode(
+                keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)"),
+                keccak256(bytes("EigenLayer")), 
+                block.chainid, 
+                address(this)
+            )
+        );
+    }
+
+    function test_domainSeparator_NonZero() public {
+        assertTrue(_INITIAL_DOMAIN_SEPARATOR != 0, "The initial domain separator should be non-zero");
+        assertTrue(domainSeparator() != 0, "The domain separator should be non-zero");
+        assertTrue(domainSeparator() == expectedDomainSeparator, "The domain separator should be as expected");
+    }
+
+    function test_domainSeparator_NewChainId() public {
+        bytes32 initialDomainSeparator = domainSeparator();
+
+        // Change the chain ID
+        vm.chainId(9999);
+
+        bytes32 newDomainSeparator = domainSeparator();
+
+        assertTrue(newDomainSeparator != 0, "The new domain separator should be non-zero");
+        assertTrue(
+            initialDomainSeparator != newDomainSeparator,
+            "The domain separator should change when the chain ID changes"
+        );
+    }
+
+    function test_checkIsValidSignatureNow_Expired() public {
+        (uint8 v, bytes32 r, bytes32 s) = vm.sign(signerPk, digest);
+
+        vm.expectRevert(ISignatureUtils.SignatureExpired.selector);
+        _checkIsValidSignatureNow(signer, digest, abi.encode(r, s, v), block.timestamp - 1);
+    }
+
+    function testFail_checkIsValidSignatureNow_InvalidSignature() public {
+        _checkIsValidSignatureNow(signer, digest, "", block.timestamp);
+    }
+}
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