diff --git a/coroio b/coroio
index fa97647..6d8214c 160000
--- a/coroio
+++ b/coroio
@@ -1 +1 @@
-Subproject commit fa976477b143c3908ffa875c9a597d4e4dd645b2
+Subproject commit 6d8214c1da12cd2ae78b280ba9f5d4eb45becd44
diff --git a/src/server.cpp b/src/server.cpp
index 045e094..f37ac99 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -11,7 +11,7 @@
 template<typename TSocket>
 NNet::TValueTask<void> TWriter<TSocket>::Write(TMessageHolder<TMessage> message) {
     auto payload = std::move(message.Payload);
-    char* p = (char*)message.Mes; // TODO: const char
+    const char* p = (const char*)message.Mes;
     uint32_t len = message->Len;
     while (len != 0) {
         auto written = co_await Socket.WriteSome(p, len);
@@ -36,11 +36,11 @@ template<typename TSocket>
 NNet::TValueTask<TMessageHolder<TMessage>> TReader<TSocket>::Read() {
     decltype(TMessage::Type) type;
     decltype(TMessage::Len) len;
-    auto s = co_await Socket.ReadSome((char*)&type, sizeof(type));
+    auto s = co_await Socket.ReadSome(&type, sizeof(type));
     if (s != sizeof(type)) {
         throw std::runtime_error("Connection closed");
     }
-    s = co_await Socket.ReadSome((char*)&len, sizeof(len));
+    s = co_await Socket.ReadSome(&len, sizeof(len));
     if (s != sizeof(len)) {
         throw std::runtime_error("Connection closed");
     }
diff --git a/test/test_raft.cpp b/test/test_raft.cpp
index a2b7573..f148d1c 100644
--- a/test/test_raft.cpp
+++ b/test/test_raft.cpp
@@ -165,8 +165,8 @@ void test_message_send_recv(void** state) {
     {
         auto client = std::move(co_await server.Accept());
         uint32_t type, len;
-        auto r = co_await client.ReadSome((char*)&type, sizeof(type));
-        r = co_await client.ReadSome((char*)&len, sizeof(len));
+        auto r = co_await client.ReadSome(&type, sizeof(type));
+        r = co_await client.ReadSome(&len, sizeof(len));
         received = NewHoldedMessage<TMessage>(type, len);
         r = co_await client.ReadSome(received->Value, len - sizeof(TMessage));
         co_return;