diff --git a/solidity/security/erc721-arbitrary-transferfrom.sol b/solidity/security/erc721-arbitrary-transferfrom.sol
index e6fe84e4b..1cffe3c4c 100644
--- a/solidity/security/erc721-arbitrary-transferfrom.sol
+++ b/solidity/security/erc721-arbitrary-transferfrom.sol
@@ -1498,8 +1498,8 @@ contract Distortion is ERC721A, Ownable, ReentrancyGuard {
 
 
   bool public isClaimActive = false;
-  uint public maxSupply = 1000;
-  uint public maxFree = 200;
+  uint public immutable maxSupply = 1000;
+  uint public constant maxFree = 200;
   uint256 public price = 0.05 ether;    
   address payable private immutable payoutAddress;
 
@@ -2032,4 +2032,4 @@ library Base64 {
 
         return string(result);
     }
-}
\ No newline at end of file
+}