diff --git a/wish/cpp/CMakeLists.txt b/wish/cpp/CMakeLists.txt
index a1989c4..583536f 100644
--- a/wish/cpp/CMakeLists.txt
+++ b/wish/cpp/CMakeLists.txt
@@ -152,6 +152,7 @@ include_directories(src)
 # Build as a static library: libevent is also static and was not compiled with
 # -fPIC, so it cannot be linked into a shared object.
 add_library(buffer_event_web_stream STATIC
+    src/web_stream.h
     src/buffer_event_web_stream.cc
     src/buffer_event_web_stream.h
     ${libevent_SOURCE_DIR}/bufferevent_openssl.c
diff --git a/wish/cpp/patches/wslay-disable-mask.patch b/wish/cpp/patches/wslay-disable-mask.patch
index 874e319..416c4cd 100644
--- a/wish/cpp/patches/wslay-disable-mask.patch
+++ b/wish/cpp/patches/wslay-disable-mask.patch
@@ -1,3 +1,15 @@
+diff --git a/lib/includes/wslay/wslay.h b/lib/includes/wslay/wslay.h
+index b73e6d8..80a5f78 100644
+--- a/lib/includes/wslay/wslay.h
++++ b/lib/includes/wslay/wslay.h
+@@ -132,6 +132,7 @@ enum wslay_opcode {
+   WSLAY_CONTINUATION_FRAME = 0x0u,
+   WSLAY_TEXT_FRAME = 0x1u,
+   WSLAY_BINARY_FRAME = 0x2u,
++  WSLAY_METADATA_FRAME = 0x3u,
+   WSLAY_CONNECTION_CLOSE = 0x8u,
+   WSLAY_PING = 0x9u,
+   WSLAY_PONG = 0xau
 diff --git a/lib/wslay_event.c b/lib/wslay_event.c
 index 4c29fe4..93e9255 100644
 --- a/lib/wslay_event.c
@@ -11,6 +23,14 @@ index 4c29fe4..93e9255 100644
          if ((r = wslay_event_queue_close_wrapper(ctx, WSLAY_CODE_PROTOCOL_ERROR,
                                                   NULL, 0)) != 0) {
            return (int)r;
+@@ -519,6 +519,7 @@ int wslay_event_recv(wslay_event_context_ptr ctx) {
+       if (ctx->imsg->opcode == 0xffu) {
+         if (iocb.opcode == WSLAY_TEXT_FRAME ||
+             iocb.opcode == WSLAY_BINARY_FRAME ||
++            iocb.opcode == WSLAY_METADATA_FRAME ||
+             iocb.opcode == WSLAY_CONNECTION_CLOSE ||
+             iocb.opcode == WSLAY_PING || iocb.opcode == WSLAY_PONG) {
+           wslay_event_imsg_set(ctx->imsg, iocb.fin, iocb.rsv, iocb.opcode);
 @@ -775,7 +775,7 @@ int wslay_event_send(wslay_event_context_ptr ctx) {
        iocb.fin = 1;
        iocb.opcode = ctx->omsg->opcode;
diff --git a/wish/cpp/src/buffer_event_web_stream_test.cc b/wish/cpp/src/buffer_event_web_stream_test.cc
index 5191d85..5d14e4a 100644
--- a/wish/cpp/src/buffer_event_web_stream_test.cc
+++ b/wish/cpp/src/buffer_event_web_stream_test.cc
@@ -234,3 +234,64 @@ TEST_F(BufferEventWebStreamTest, CloseSignalsEOF) {
   // Only delete server.
   delete server;
 }
+
+// Verify that metadata frames (opcode = 3) can be sent and received correctly by both client and server.
+TEST_F(BufferEventWebStreamTest, HandshakeAndMetadataExchange) {
+  bufferevent* pair[2];
+  int rv = bufferevent_pair_new(base_,
+                                BEV_OPT_CLOSE_ON_FREE | BEV_OPT_DEFER_CALLBACKS,
+                                pair);
+  ASSERT_EQ(rv, 0);
+
+  BufferEventWebStream* server = new BufferEventWebStream(pair[0], true /* is_server */);
+  BufferEventWebStream* client = new BufferEventWebStream(pair[1], false /* is_server */);
+
+  bool server_opened = false;
+  bool client_opened = false;
+  std::string metadata_from_client;
+  std::string metadata_from_server;
+
+  server->SetOnOpen([&]() {
+    server_opened = true;
+    server->SendMetadata("Server Metadata");
+  });
+
+  client->SetOnOpen([&]() {
+    client_opened = true;
+    client->SendMetadata("Client Metadata");
+  });
+
+  auto check_done = [&]() {
+    if (!metadata_from_client.empty() && !metadata_from_server.empty()) {
+      event_base_loopbreak(base_);
+    }
+  };
+
+  server->SetOnMessage([&](uint8_t opcode, const std::string& msg) {
+    if (opcode == WEB_STREAM_OPCODE_METADATA) {
+      metadata_from_client = msg;
+    }
+    check_done();
+  });
+
+  client->SetOnMessage([&](uint8_t opcode, const std::string& msg) {
+    if (opcode == WEB_STREAM_OPCODE_METADATA) {
+      metadata_from_server = msg;
+    }
+    check_done();
+  });
+
+  server->Start();
+  client->Start();
+
+  event_base_dispatch(base_);
+
+  EXPECT_TRUE(client_opened);
+  EXPECT_TRUE(server_opened);
+  EXPECT_EQ(metadata_from_client, "Client Metadata");
+  EXPECT_EQ(metadata_from_server, "Server Metadata");
+
+  delete server;
+  delete client;
+}
+