diff --git a/src/tokens/ERC20.sol b/src/tokens/ERC20.sol
index d7d26c95..63e86d28 100644
--- a/src/tokens/ERC20.sol
+++ b/src/tokens/ERC20.sol
@@ -38,9 +38,6 @@ abstract contract ERC20 {
                              EIP-2612 STORAGE
     //////////////////////////////////////////////////////////////*/
 
-    bytes32 internal constant PERMIT_TYPEHASH =
-        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
-
     uint256 internal immutable INITIAL_CHAIN_ID;
 
     bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;
@@ -134,7 +131,18 @@ abstract contract ERC20 {
                 abi.encodePacked(
                     "\x19\x01",
                     DOMAIN_SEPARATOR(),
-                    keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
+                    keccak256(
+                        abi.encode(
+                            keccak256(
+                                "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
+                            ),
+                            owner,
+                            spender,
+                            value,
+                            nonces[owner]++,
+                            deadline
+                        )
+                    )
                 )
             );