diff --git a/foundry.toml b/foundry.toml
index e3381ae4..46d3e278 100644
--- a/foundry.toml
+++ b/foundry.toml
@@ -4,6 +4,7 @@ out = 'out'
 libs = ['lib']
 solc = "0.8.27"
 solc-version = "0.8.27"
+evm_version = "paris"
 via_ir = true
 use_literal_content = true
 
diff --git a/src/tokens/ERC1155/presets/pack/ERC1155Pack.sol b/src/tokens/ERC1155/presets/pack/ERC1155Pack.sol
index a3dcde6b..9c5586a5 100644
--- a/src/tokens/ERC1155/presets/pack/ERC1155Pack.sol
+++ b/src/tokens/ERC1155/presets/pack/ERC1155Pack.sol
@@ -6,7 +6,7 @@ import { ERC1155Items } from "../items/ERC1155Items.sol";
 import { IERC1155ItemsFunctions } from "../items/IERC1155Items.sol";
 import { IERC1155Pack } from "./IERC1155Pack.sol";
 
-import { MerkleProof } from "openzeppelin-contracts/contracts/utils/cryptography/MerkleProof.sol";
+import { MerkleProofLib } from "solady/utils/MerkleProofLib.sol";
 
 contract ERC1155Pack is ERC1155Items, IERC1155Pack {
 
@@ -59,9 +59,6 @@ contract ERC1155Pack is ERC1155Items, IERC1155Pack {
         if (_commitments[packId][msg.sender] != 0) {
             revert PendingReveal();
         }
-        if (balanceOf(msg.sender, packId) == 0) {
-            revert NoBalance();
-        }
         _burn(msg.sender, packId, 1);
         uint256 revealAfterBlock = block.number + 1;
         _commitments[packId][msg.sender] = revealAfterBlock;
@@ -79,7 +76,7 @@ contract ERC1155Pack is ERC1155Items, IERC1155Pack {
         (uint256 randomIndex, uint256 revealIdx) = _getRevealIdx(user, packId);
 
         bytes32 leaf = keccak256(abi.encode(revealIdx, packContent));
-        if (!MerkleProof.verify(proof, merkleRoot[packId], leaf)) {
+        if (!MerkleProofLib.verify(proof, merkleRoot[packId], leaf)) {
             revert InvalidProof();
         }
 
@@ -106,10 +103,11 @@ contract ERC1155Pack is ERC1155Items, IERC1155Pack {
 
     /// @inheritdoc IERC1155Pack
     function refundPack(address user, uint256 packId) external {
-        if (_commitments[packId][user] == 0) {
+        uint256 commitment = _commitments[packId][user];
+        if (commitment == 0) {
             revert NoCommit();
         }
-        if (uint256(blockhash(_commitments[packId][user])) != 0 || block.number <= _commitments[packId][user]) {
+        if (uint256(blockhash(commitment)) != 0 || block.number <= commitment) {
             revert PendingReveal();
         }
         delete _commitments[packId][user];
@@ -127,15 +125,15 @@ contract ERC1155Pack is ERC1155Items, IERC1155Pack {
             revert AllPacksOpened();
         }
 
-        bytes32 blockHash = blockhash(_commitments[packId][user]);
+        uint256 commitment = _commitments[packId][user];
+        if (commitment == 0) {
+            revert NoCommit();
+        }
+        bytes32 blockHash = blockhash(commitment);
         if (uint256(blockHash) == 0) {
             revert InvalidCommit();
         }
 
-        if (_commitments[packId][user] == 0) {
-            revert NoCommit();
-        }
-
         randomIdx = uint256(keccak256(abi.encode(blockHash, user))) % remainingSupply[packId];
         revealIdx = _getIndexOrDefault(randomIdx, packId);
         return (randomIdx, revealIdx);
diff --git a/src/tokens/ERC1155/presets/pack/IERC1155Pack.sol b/src/tokens/ERC1155/presets/pack/IERC1155Pack.sol
index b11946cd..4ce780bf 100644
--- a/src/tokens/ERC1155/presets/pack/IERC1155Pack.sol
+++ b/src/tokens/ERC1155/presets/pack/IERC1155Pack.sol
@@ -25,11 +25,6 @@ interface IERC1155Pack {
      */
     error NoCommit();
 
-    /**
-     * No balance.
-     */
-    error NoBalance();
-
     /**
      * Invalid proof.
      */
diff --git a/test/tokens/ERC1155/presets/ERC1155Pack.t.sol b/test/tokens/ERC1155/presets/ERC1155Pack.t.sol
index c54c98de..07722881 100644
--- a/test/tokens/ERC1155/presets/ERC1155Pack.t.sol
+++ b/test/tokens/ERC1155/presets/ERC1155Pack.t.sol
@@ -18,6 +18,8 @@ import { IERC165 } from "openzeppelin-contracts/contracts/utils/introspection/IE
 
 import { ISignalsImplicitMode } from "signals-implicit-mode/src/helper/SignalsImplicitMode.sol";
 
+import { ERC1155 } from "solady/tokens/ERC1155.sol";
+
 contract ERC1155PackHack is ERC1155Pack {
 
     function setAllExceptOneClaimed(
@@ -218,7 +220,7 @@ contract ERC1155PackTest is TestHelper, IERC1155ItemsSignals {
     ) public {
         assumeSafeAddress(user);
         vm.prank(user);
-        vm.expectRevert(IERC1155Pack.NoBalance.selector);
+        vm.expectRevert(ERC1155.InsufficientBalance.selector);
         pack.commit(0);
     }