diff --git a/src/engine_api/engine_api.zig b/src/engine_api/engine_api.zig
index 43dd956..b786f7a 100644
--- a/src/engine_api/engine_api.zig
+++ b/src/engine_api/engine_api.zig
@@ -91,13 +91,15 @@ test "deserialize sample engine_newPayloadV2" {
     const AccountState = lib.state.AccountState;
     const BlockHeader = lib.blockchain.BlockHeader;
     const Hash32 = lib.types.Hash32;
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
 
     const fileContent = @embedFile("./test_req.json");
 
-    const payload = try json.parseFromSlice(EngineAPIRequest, std.testing.allocator, fileContent, .{ .ignore_unknown_fields = true });
+    const payload = try json.parseFromSlice(EngineAPIRequest, arena.allocator(), fileContent, .{ .ignore_unknown_fields = true });
     defer payload.deinit();
 
-    var statedb = try StateDB.init(std.testing.allocator, &[0]AccountState{});
+    var statedb = try StateDB.init(arena.allocator(), &[0]AccountState{});
     defer statedb.deinit();
     const parent_header = BlockHeader{
         .parent_hash = [_]u8{0} ** 32,
@@ -118,11 +120,11 @@ test "deserialize sample engine_newPayloadV2" {
         .base_fee_per_gas = 7,
         .withdrawals_root = [_]u8{0} ** 32,
     };
-    var blockchain = try Blockchain.init(std.testing.allocator, .Testing, &statedb, parent_header, [_]Hash32{[_]u8{0} ** 32} ** 256);
+    var blockchain = try Blockchain.init(arena.allocator(), .Testing, &statedb, parent_header, [_]Hash32{[_]u8{0} ** 32} ** 256);
 
     try expect(std.mem.eql(u8, payload.value.method, "engine_newPayloadV2"));
     const execution_payload_json = payload.value.params[0];
-    var ep = try execution_payload_json.to_execution_payload(std.testing.allocator);
-    defer ep.deinit(std.testing.allocator);
+    var ep = try execution_payload_json.to_execution_payload(arena.allocator());
+    defer ep.deinit(arena.allocator());
     try execution_payload.newPayloadV2Handler(&blockchain, &ep);
 }
diff --git a/src/engine_api/execution_payload.zig b/src/engine_api/execution_payload.zig
index 208e81c..4f8a55d 100644
--- a/src/engine_api/execution_payload.zig
+++ b/src/engine_api/execution_payload.zig
@@ -48,9 +48,9 @@ pub const ExecutionPayload = struct {
                 .timestamp = @intCast(self.timestamp),
                 .extra_data = self.extraData,
                 .base_fee_per_gas = self.baseFeePerGas,
-                .transactions_root = [_]u8{0} ** 32,
+                .transactions_root = lib.mpt.empty_mpt_root,
                 .nonce = [_]u8{0} ** 8,
-                .withdrawals_root = [_]u8{0} ** 32,
+                .withdrawals_root = lib.mpt.empty_mpt_root,
             },
             .transactions = self.transactions,
             .withdrawals = self.withdrawals,
diff --git a/src/engine_api/test_req.json b/src/engine_api/test_req.json
index 07a3ff6..2e9b631 100644
--- a/src/engine_api/test_req.json
+++ b/src/engine_api/test_req.json
@@ -4,7 +4,7 @@
   "method": "engine_newPayloadV2",
   "params": [
     {
-      "parentHash": "0x522930864dc2f6569f4d4b92f40001fe6752727ff53db5cb5c5ffd51d3cc53e4",
+      "parentHash": "0xf725aca23ac424e82c9e75b78915bc533a4d4be2ced7c57f0f5885c5ac8e03d5",
       "feeRecipient": "0xf97e180c050e5ab072211ad2c213eb5aee4df134",
       "stateRoot": "0x27bb13dc19c41288dd29236b27baac49338c466b8c0eb44fb4c0c0083dfb214a",
       "receiptsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
diff --git a/src/mpt/mpt.zig b/src/mpt/mpt.zig
index 3019be4..bca92ea 100644
--- a/src/mpt/mpt.zig
+++ b/src/mpt/mpt.zig
@@ -7,7 +7,7 @@ const common = @import("../common/common.zig");
 const Allocator = std.mem.Allocator;
 const Hash32 = types.Hash32;
 
-const empty_mpt_root = common.comptimeHexToBytes("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421");
+pub const empty_mpt_root = common.comptimeHexToBytes("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421");
 
 // KeyVal represents an element in the Merkle Patricia Trie.
 pub const KeyVal = struct {