diff --git a/src/ray/common/client_connection.cc b/src/ray/common/client_connection.cc
index 1ca93ba2a..dde14d680 100644
--- a/src/ray/common/client_connection.cc
+++ b/src/ray/common/client_connection.cc
@@ -186,9 +186,10 @@ void ServerConnection<T>::DoAsyncWrites() {
 template <class T>
 std::shared_ptr<ClientConnection<T>> ClientConnection<T>::Create(
     ClientHandler<T> &client_handler, MessageHandler<T> &message_handler,
-    boost::asio::basic_stream_socket<T> &&socket, const std::string &debug_label) {
-  std::shared_ptr<ClientConnection<T>> self(
-      new ClientConnection(message_handler, std::move(socket), debug_label));
+    boost::asio::basic_stream_socket<T> &&socket, const std::string &debug_label,
+    int64_t error_message_type) {
+  std::shared_ptr<ClientConnection<T>> self(new ClientConnection(
+      message_handler, std::move(socket), debug_label, error_message_type));
   // Let our manager process our new connection.
   client_handler(*self);
   return self;
@@ -197,10 +198,12 @@ std::shared_ptr<ClientConnection<T>> ClientConnection<T>::Create(
 template <class T>
 ClientConnection<T>::ClientConnection(MessageHandler<T> &message_handler,
                                       boost::asio::basic_stream_socket<T> &&socket,
-                                      const std::string &debug_label)
+                                      const std::string &debug_label,
+                                      int64_t error_message_type)
     : ServerConnection<T>(std::move(socket)),
       message_handler_(message_handler),
-      debug_label_(debug_label) {}
+      debug_label_(debug_label),
+      error_message_type_(error_message_type) {}
 
 template <class T>
 const ClientID &ClientConnection<T>::GetClientId() {
@@ -230,7 +233,7 @@ template <class T>
 void ClientConnection<T>::ProcessMessageHeader(const boost::system::error_code &error) {
   if (error) {
     // If there was an error, disconnect the client.
-    read_type_ = static_cast<int64_t>(protocol::MessageType::DisconnectClient);
+    read_type_ = error_message_type_;
     read_length_ = 0;
     ProcessMessage(error);
     return;
@@ -251,7 +254,7 @@ void ClientConnection<T>::ProcessMessageHeader(const boost::system::error_code &
 template <class T>
 void ClientConnection<T>::ProcessMessage(const boost::system::error_code &error) {
   if (error) {
-    read_type_ = static_cast<int64_t>(protocol::MessageType::DisconnectClient);
+    read_type_ = error_message_type_;
   }
 
   int64_t start_ms = current_time_ms();
diff --git a/src/ray/common/client_connection.h b/src/ray/common/client_connection.h
index 7246c2b81..2aee25681 100644
--- a/src/ray/common/client_connection.h
+++ b/src/ray/common/client_connection.h
@@ -148,7 +148,8 @@ class ClientConnection : public ServerConnection<T> {
   /// \return std::shared_ptr<ClientConnection>.
   static std::shared_ptr<ClientConnection<T>> Create(
       ClientHandler<T> &new_client_handler, MessageHandler<T> &message_handler,
-      boost::asio::basic_stream_socket<T> &&socket, const std::string &debug_label);
+      boost::asio::basic_stream_socket<T> &&socket, const std::string &debug_label,
+      int64_t error_message_type);
 
   std::shared_ptr<ClientConnection<T>> shared_ClientConnection_from_this() {
     return std::static_pointer_cast<ClientConnection<T>>(shared_from_this());
@@ -169,7 +170,7 @@ class ClientConnection : public ServerConnection<T> {
   /// A private constructor for a node client connection.
   ClientConnection(MessageHandler<T> &message_handler,
                    boost::asio::basic_stream_socket<T> &&socket,
-                   const std::string &debug_label);
+                   const std::string &debug_label, int64_t error_message_type);
   /// Process an error from the last operation, then process the  message
   /// header from the client.
   void ProcessMessageHeader(const boost::system::error_code &error);
@@ -183,6 +184,8 @@ class ClientConnection : public ServerConnection<T> {
   MessageHandler<T> message_handler_;
   /// A label used for debug messages.
   const std::string debug_label_;
+  /// The value for disconnect client message.
+  int64_t error_message_type_;
   /// Buffers for the current message being read from the client.
   int64_t read_version_;
   int64_t read_type_;
diff --git a/src/ray/object_manager/format/object_manager.fbs b/src/ray/object_manager/format/object_manager.fbs
index 4b684ff89..dbafa3744 100644
--- a/src/ray/object_manager/format/object_manager.fbs
+++ b/src/ray/object_manager/format/object_manager.fbs
@@ -27,6 +27,7 @@ table ObjectInfo {
 
 enum MessageType:int {
   ConnectClient = 1,
+  DisconnectClient,
   PushRequest,
   PullRequest,
   FreeRequest
diff --git a/src/ray/object_manager/object_buffer_pool.cc b/src/ray/object_manager/object_buffer_pool.cc
index 15e9eefac..f7d1f1651 100644
--- a/src/ray/object_manager/object_buffer_pool.cc
+++ b/src/ray/object_manager/object_buffer_pool.cc
@@ -150,7 +150,6 @@ void ObjectBufferPool::SealChunk(const ObjectID &object_id, const uint64_t chunk
             CreateChunkState::REFERENCED);
   create_buffer_state_[object_id].chunk_state[chunk_index] = CreateChunkState::SEALED;
   create_buffer_state_[object_id].num_seals_remaining--;
-  RAY_CHECK(create_buffer_state_[object_id].num_seals_remaining >= 0);
   RAY_LOG(DEBUG) << "SealChunk" << object_id << " "
                  << create_buffer_state_[object_id].num_seals_remaining;
   if (create_buffer_state_[object_id].num_seals_remaining == 0) {
diff --git a/src/ray/object_manager/object_manager.cc b/src/ray/object_manager/object_manager.cc
index 6afc5f3dc..517d01c4a 100644
--- a/src/ray/object_manager/object_manager.cc
+++ b/src/ray/object_manager/object_manager.cc
@@ -707,25 +707,26 @@ void ObjectManager::ProcessNewClient(TcpClientConnection &conn) {
 
 void ObjectManager::ProcessClientMessage(std::shared_ptr<TcpClientConnection> &conn,
                                          int64_t message_type, const uint8_t *message) {
-  switch (message_type) {
-  case static_cast<int64_t>(object_manager_protocol::MessageType::PushRequest): {
+  auto message_type_value =
+      static_cast<object_manager_protocol::MessageType>(message_type);
+  switch (message_type_value) {
+  case object_manager_protocol::MessageType::PushRequest: {
     ReceivePushRequest(conn, message);
     break;
   }
-  case static_cast<int64_t>(object_manager_protocol::MessageType::PullRequest): {
+  case object_manager_protocol::MessageType::PullRequest: {
     ReceivePullRequest(conn, message);
     break;
   }
-  case static_cast<int64_t>(object_manager_protocol::MessageType::ConnectClient): {
+  case object_manager_protocol::MessageType::ConnectClient: {
     ConnectClient(conn, message);
     break;
   }
-  case static_cast<int64_t>(object_manager_protocol::MessageType::FreeRequest): {
+  case object_manager_protocol::MessageType::FreeRequest: {
     ReceiveFreeRequest(conn, message);
     break;
   }
-  case static_cast<int64_t>(protocol::MessageType::DisconnectClient): {
-    // TODO(hme): Disconnect without depending on the node manager protocol.
+  case object_manager_protocol::MessageType::DisconnectClient: {
     DisconnectClient(conn, message);
     break;
   }
diff --git a/src/ray/object_manager/test/object_manager_stress_test.cc b/src/ray/object_manager/test/object_manager_stress_test.cc
index 84e27e5ed..b8b35ad62 100644
--- a/src/ray/object_manager/test/object_manager_stress_test.cc
+++ b/src/ray/object_manager/test/object_manager_stress_test.cc
@@ -74,9 +74,10 @@ class MockServer {
       object_manager_.ProcessClientMessage(client, message_type, message);
     };
     // Accept a new local client and dispatch it to the node manager.
-    auto new_connection =
-        TcpClientConnection::Create(client_handler, message_handler,
-                                    std::move(object_manager_socket_), "object manager");
+    auto new_connection = TcpClientConnection::Create(
+        client_handler, message_handler, std::move(object_manager_socket_),
+        "object manager",
+        static_cast<int64_t>(object_manager::protocol::MessageType::DisconnectClient));
     DoAcceptObjectManager();
   }
 
diff --git a/src/ray/object_manager/test/object_manager_test.cc b/src/ray/object_manager/test/object_manager_test.cc
index 4c108f2d3..12ad2c52c 100644
--- a/src/ray/object_manager/test/object_manager_test.cc
+++ b/src/ray/object_manager/test/object_manager_test.cc
@@ -65,9 +65,10 @@ class MockServer {
       object_manager_.ProcessClientMessage(client, message_type, message);
     };
     // Accept a new local client and dispatch it to the node manager.
-    auto new_connection =
-        TcpClientConnection::Create(client_handler, message_handler,
-                                    std::move(object_manager_socket_), "object manager");
+    auto new_connection = TcpClientConnection::Create(
+        client_handler, message_handler, std::move(object_manager_socket_),
+        "object manager",
+        static_cast<int64_t>(object_manager::protocol::MessageType::DisconnectClient));
     DoAcceptObjectManager();
   }
 
diff --git a/src/ray/raylet/client_connection_test.cc b/src/ray/raylet/client_connection_test.cc
index a68a6535c..5623beb90 100644
--- a/src/ray/raylet/client_connection_test.cc
+++ b/src/ray/raylet/client_connection_test.cc
@@ -13,7 +13,8 @@ namespace raylet {
 
 class ClientConnectionTest : public ::testing::Test {
  public:
-  ClientConnectionTest() : io_service_(), in_(io_service_), out_(io_service_) {
+  ClientConnectionTest()
+      : io_service_(), in_(io_service_), out_(io_service_), error_message_type_(1) {
     boost::asio::local::connect_pair(in_, out_);
   }
 
@@ -21,6 +22,7 @@ class ClientConnectionTest : public ::testing::Test {
   boost::asio::io_service io_service_;
   boost::asio::local::stream_protocol::socket in_;
   boost::asio::local::stream_protocol::socket out_;
+  int64_t error_message_type_;
 };
 
 TEST_F(ClientConnectionTest, SimpleSyncWrite) {
@@ -37,11 +39,11 @@ TEST_F(ClientConnectionTest, SimpleSyncWrite) {
         num_messages += 1;
       };
 
-  auto conn1 = LocalClientConnection::Create(client_handler, message_handler,
-                                             std::move(in_), "conn1");
+  auto conn1 = LocalClientConnection::Create(
+      client_handler, message_handler, std::move(in_), "conn1", error_message_type_);
 
-  auto conn2 = LocalClientConnection::Create(client_handler, message_handler,
-                                             std::move(out_), "conn2");
+  auto conn2 = LocalClientConnection::Create(
+      client_handler, message_handler, std::move(out_), "conn2", error_message_type_);
 
   RAY_CHECK_OK(conn1->WriteMessage(0, 5, arr));
   RAY_CHECK_OK(conn2->WriteMessage(0, 5, arr));
@@ -83,11 +85,11 @@ TEST_F(ClientConnectionTest, SimpleAsyncWrite) {
         }
       };
 
-  auto writer = LocalClientConnection::Create(client_handler, noop_handler,
-                                              std::move(in_), "writer");
+  auto writer = LocalClientConnection::Create(
+      client_handler, noop_handler, std::move(in_), "writer", error_message_type_);
 
   reader = LocalClientConnection::Create(client_handler, message_handler, std::move(out_),
-                                         "reader");
+                                         "reader", error_message_type_);
 
   std::function<void(const ray::Status &)> callback = [](const ray::Status &status) {
     RAY_CHECK_OK(status);
@@ -111,8 +113,8 @@ TEST_F(ClientConnectionTest, SimpleAsyncError) {
       std::shared_ptr<LocalClientConnection> client, int64_t message_type,
       const uint8_t *message) {};
 
-  auto writer = LocalClientConnection::Create(client_handler, noop_handler,
-                                              std::move(in_), "writer");
+  auto writer = LocalClientConnection::Create(
+      client_handler, noop_handler, std::move(in_), "writer", error_message_type_);
 
   std::function<void(const ray::Status &)> callback = [](const ray::Status &status) {
     ASSERT_TRUE(!status.ok());
@@ -133,8 +135,8 @@ TEST_F(ClientConnectionTest, CallbackWithSharedRefDoesNotLeakConnection) {
       std::shared_ptr<LocalClientConnection> client, int64_t message_type,
       const uint8_t *message) {};
 
-  auto writer = LocalClientConnection::Create(client_handler, noop_handler,
-                                              std::move(in_), "writer");
+  auto writer = LocalClientConnection::Create(
+      client_handler, noop_handler, std::move(in_), "writer", error_message_type_);
 
   std::function<void(const ray::Status &)> callback =
       [writer](const ray::Status &status) {
diff --git a/src/ray/raylet/raylet.cc b/src/ray/raylet/raylet.cc
index 39028ce7f..23f0dba6c 100644
--- a/src/ray/raylet/raylet.cc
+++ b/src/ray/raylet/raylet.cc
@@ -101,7 +101,8 @@ void Raylet::HandleAcceptNodeManager(const boost::system::error_code &error) {
     };
     // Accept a new TCP client and dispatch it to the node manager.
     auto new_connection = TcpClientConnection::Create(
-        client_handler, message_handler, std::move(node_manager_socket_), "node manager");
+        client_handler, message_handler, std::move(node_manager_socket_), "node manager",
+        static_cast<int64_t>(protocol::MessageType::DisconnectClient));
   }
   // We're ready to accept another client.
   DoAcceptNodeManager();
@@ -122,9 +123,10 @@ void Raylet::HandleAcceptObjectManager(const boost::system::error_code &error) {
     object_manager_.ProcessClientMessage(client, message_type, message);
   };
   // Accept a new TCP client and dispatch it to the node manager.
-  auto new_connection =
-      TcpClientConnection::Create(client_handler, message_handler,
-                                  std::move(object_manager_socket_), "object manager");
+  auto new_connection = TcpClientConnection::Create(
+      client_handler, message_handler, std::move(object_manager_socket_),
+      "object manager",
+      static_cast<int64_t>(object_manager::protocol::MessageType::DisconnectClient));
   DoAcceptObjectManager();
 }
 
@@ -144,8 +146,9 @@ void Raylet::HandleAccept(const boost::system::error_code &error) {
       node_manager_.ProcessClientMessage(client, message_type, message);
     };
     // Accept a new local client and dispatch it to the node manager.
-    auto new_connection = LocalClientConnection::Create(client_handler, message_handler,
-                                                        std::move(socket_), "worker");
+    auto new_connection = LocalClientConnection::Create(
+        client_handler, message_handler, std::move(socket_), "worker",
+        static_cast<int64_t>(protocol::MessageType::DisconnectClient));
   }
   // We're ready to accept another client.
   DoAccept();
diff --git a/src/ray/raylet/worker_pool_test.cc b/src/ray/raylet/worker_pool_test.cc
index 9b228457b..d235d0244 100644
--- a/src/ray/raylet/worker_pool_test.cc
+++ b/src/ray/raylet/worker_pool_test.cc
@@ -34,7 +34,7 @@ class WorkerPoolMock : public WorkerPool {
 
 class WorkerPoolTest : public ::testing::Test {
  public:
-  WorkerPoolTest() : worker_pool_(), io_service_() {}
+  WorkerPoolTest() : worker_pool_(), io_service_(), error_message_type_(1) {}
 
   std::shared_ptr<Worker> CreateWorker(pid_t pid,
                                        const Language &language = Language::PYTHON) {
@@ -46,14 +46,16 @@ class WorkerPoolTest : public ::testing::Test {
           HandleMessage(client, message_type, message);
         };
     boost::asio::local::stream_protocol::socket socket(io_service_);
-    auto client = LocalClientConnection::Create(client_handler, message_handler,
-                                                std::move(socket), "worker");
+    auto client =
+        LocalClientConnection::Create(client_handler, message_handler, std::move(socket),
+                                      "worker", error_message_type_);
     return std::shared_ptr<Worker>(new Worker(pid, language, client));
   }
 
  protected:
   WorkerPoolMock worker_pool_;
   boost::asio::io_service io_service_;
+  int64_t error_message_type_;
 
  private:
   void HandleNewClient(LocalClientConnection &){};