diff --git a/src/engine_api/engine_api.zig b/src/engine_api/engine_api.zig
index 03c1c5d..b9ed86c 100644
--- a/src/engine_api/engine_api.zig
+++ b/src/engine_api/engine_api.zig
@@ -56,6 +56,7 @@ const AllPossibleExecutionParams = struct {
             .withdrawals = null,
             .blobGasUsed = null,
             .excessBlobGas = null,
+            .allocator = allocator,
         };
 
         _ = try common.prefixedhex2hash(ret.parentHash[0..], self.parentHash);
@@ -97,6 +98,6 @@ test "deserialize sample engine_newPayloadV2" {
 
     try expect(std.mem.eql(u8, payload.value.method, "engine_newPayloadV2"));
     const execution_payload_json = payload.value.params[0];
-    const ep = try execution_payload_json.to_execution_payload(std.testing.allocator);
+    var ep = try execution_payload_json.to_execution_payload(std.testing.allocator);
     try execution_payload.newPayloadV2Handler(&ep, std.testing.allocator);
 }
diff --git a/src/engine_api/execution_payload.zig b/src/engine_api/execution_payload.zig
index f43c3dd..0ac3271 100644
--- a/src/engine_api/execution_payload.zig
+++ b/src/engine_api/execution_payload.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const types = @import("../types/types.zig");
+const Allocator = std.mem.Allocator;
 
 pub const ExecutionPayload = struct {
     parentHash: types.Hash32,
@@ -22,6 +23,8 @@ pub const ExecutionPayload = struct {
     excessBlobGas: ?u64,
     // executionWitness : ?types.ExecutionWitness,
 
+    allocator: Allocator,
+
     pub fn to_block(self: *const ExecutionPayload) types.Block {
         return types.Block{
             .header = types.BlockHeader{
@@ -50,9 +53,15 @@ pub const ExecutionPayload = struct {
             // .withdrawals = self.withdrawals,
         };
     }
+
+    pub fn deinit(self: *ExecutionPayload, allocator: std.mem.Allocator) void {
+        if (self.extraData.len > 0) {
+            allocator.free(self.extraData);
+        }
+    }
 };
 
-pub fn newPayloadV2Handler(params: *const ExecutionPayload, allocator: std.mem.Allocator) !void {
+pub fn newPayloadV2Handler(params: *ExecutionPayload, allocator: std.mem.Allocator) !void {
     // TODO reconstruct the proof from the (currently undefined) execution witness
     // and verify it. Then execute the block and return the result.
     // vm.run_block(params.to_block(), params.transactions);
@@ -61,5 +70,6 @@ pub fn newPayloadV2Handler(params: *const ExecutionPayload, allocator: std.mem.A
     std.log.info("newPayloadV2Handler: {any}", .{params});
 
     var block = params.to_block();
-    block.deinit(allocator);
+    std.debug.print("block number={}\n", .{block.header.block_number});
+    params.deinit(allocator);
 }
diff --git a/src/main.zig b/src/main.zig
index 6a8c4a8..d9b2a9e 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -26,7 +26,7 @@ fn engineAPIHandler(r: zap.SimpleRequest) void {
 
     if (std.mem.eql(u8, payload.value.method, "engine_newPayloadV2")) {
         const execution_payload_json = payload.value.params[0];
-        const execution_payload = execution_payload_json.to_execution_payload(allocator) catch |err| {
+        var execution_payload = execution_payload_json.to_execution_payload(allocator) catch |err| {
             std.log.warn("error parsing execution payload: {}", .{err});
             r.setStatus(.bad_request);
             return;
diff --git a/src/types/block.zig b/src/types/block.zig
index ad3f6de..a114617 100644
--- a/src/types/block.zig
+++ b/src/types/block.zig
@@ -17,12 +17,6 @@ pub const Block = struct {
         // TODO: consider strict checking of returned deserialized length vs rlp_bytes.len.
         return block;
     }
-
-    pub fn deinit(self: *Block, allocator: std.mem.Allocator) void {
-        if (self.header.extra_data.len > 0) {
-            allocator.free(self.header.extra_data);
-        }
-    }
 };
 
 pub const empty_uncle_hash: types.Hash32 = [_]u8{ 29, 204, 77, 232, 222, 199, 93, 122, 171, 133, 181, 103, 182, 204, 212, 26, 211, 18, 69, 27, 148, 138, 116, 19, 240, 161, 66, 253, 64, 212, 147, 71 };