diff --git a/BUILD.gn b/BUILD.gn
index 4171f62bbd..e3ebd1d940 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -763,9 +763,9 @@ dawn_generator("libdawn_wire_gen") {
     "dawn_wire/client/ApiObjects_autogen.h",
     "dawn_wire/client/ApiProcs_autogen.cpp",
     "dawn_wire/client/ApiProcs_autogen.h",
+    "dawn_wire/client/ClientBase_autogen.h",
     "dawn_wire/client/ClientHandlers_autogen.cpp",
     "dawn_wire/client/ClientPrototypes_autogen.inl",
-    "dawn_wire/client/Device_autogen.h",
     "dawn_wire/server/ServerBase_autogen.h",
     "dawn_wire/server/ServerCallbacks_autogen.cpp",
     "dawn_wire/server/ServerHandlers_autogen.cpp",
@@ -795,6 +795,8 @@ dawn_component("libdawn_wire") {
     "src/dawn_wire/client/Client.cpp",
     "src/dawn_wire/client/Client.h",
     "src/dawn_wire/client/ClientHandlers.cpp",
+    "src/dawn_wire/client/Device.cpp",
+    "src/dawn_wire/client/Device.h",
     "src/dawn_wire/client/Fence.cpp",
     "src/dawn_wire/client/Fence.h",
     "src/dawn_wire/client/ObjectAllocator.h",
diff --git a/generator/main.py b/generator/main.py
index ab4c6c7abc..bbc08691f3 100644
--- a/generator/main.py
+++ b/generator/main.py
@@ -387,9 +387,9 @@ def get_renders_for_targets(api_params, wire_json, targets):
         renders.append(FileRender('dawn_wire/client/ApiObjects.h', 'dawn_wire/client/ApiObjects_autogen.h', wire_params))
         renders.append(FileRender('dawn_wire/client/ApiProcs.cpp', 'dawn_wire/client/ApiProcs_autogen.cpp', wire_params))
         renders.append(FileRender('dawn_wire/client/ApiProcs.h', 'dawn_wire/client/ApiProcs_autogen.h', wire_params))
+        renders.append(FileRender('dawn_wire/client/ClientBase.h', 'dawn_wire/client/ClientBase_autogen.h', wire_params))
         renders.append(FileRender('dawn_wire/client/ClientHandlers.cpp', 'dawn_wire/client/ClientHandlers_autogen.cpp', wire_params))
         renders.append(FileRender('dawn_wire/client/ClientPrototypes.inl', 'dawn_wire/client/ClientPrototypes_autogen.inl', wire_params))
-        renders.append(FileRender('dawn_wire/client/Device.h', 'dawn_wire/client/Device_autogen.h', wire_params))
         renders.append(FileRender('dawn_wire/server/ServerBase.h', 'dawn_wire/server/ServerBase_autogen.h', wire_params))
         renders.append(FileRender('dawn_wire/server/ServerCallbacks.cpp', 'dawn_wire/server/ServerCallbacks_autogen.cpp', wire_params))
         renders.append(FileRender('dawn_wire/server/ServerHandlers.cpp', 'dawn_wire/server/ServerHandlers_autogen.cpp', wire_params))
diff --git a/generator/templates/dawn_wire/client/ApiProcs.cpp b/generator/templates/dawn_wire/client/ApiProcs.cpp
index 9544e93dd9..a5c628209d 100644
--- a/generator/templates/dawn_wire/client/ApiProcs.cpp
+++ b/generator/templates/dawn_wire/client/ApiProcs.cpp
@@ -15,7 +15,6 @@
 #include "dawn_wire/client/ApiObjects.h"
 #include "dawn_wire/client/ApiProcs_autogen.h"
 #include "dawn_wire/client/Client.h"
-#include "dawn_wire/client/Device_autogen.h"
 
 namespace dawn_wire { namespace client {
     //* Implementation of the client API functions.
@@ -42,7 +41,7 @@ namespace dawn_wire { namespace client {
 
                     //* For object creation, store the object ID the client will use for the result.
                     {% if method.return_type.category == "object" %}
-                        auto* allocation = self->device->{{method.return_type.name.camelCase()}}.New();
+                        auto* allocation = self->device->GetClient()->{{method.return_type.name.CamelCase()}}Allocator().New(self->device);
 
                         {% if type.is_builder %}
                             //* We are in GetResult, so the callback that should be called is the
@@ -61,8 +60,8 @@ namespace dawn_wire { namespace client {
 
                     //* Allocate space to send the command and copy the value args over.
                     size_t requiredSize = cmd.GetRequiredSize();
-                    char* allocatedBuffer = static_cast<char*>(device->GetCmdSpace(requiredSize));
-                    cmd.Serialize(allocatedBuffer, *device);
+                    char* allocatedBuffer = static_cast<char*>(device->GetClient()->GetCmdSpace(requiredSize));
+                    cmd.Serialize(allocatedBuffer, *device->GetClient());
 
                     {% if method.return_type.category == "object" %}
                         return reinterpret_cast<{{as_cType(method.return_type.name)}}>(allocation->object.get());
@@ -100,10 +99,10 @@ namespace dawn_wire { namespace client {
                 cmd.objectId = obj->id;
 
                 size_t requiredSize = cmd.GetRequiredSize();
-                char* allocatedBuffer = static_cast<char*>(obj->device->GetCmdSpace(requiredSize));
+                char* allocatedBuffer = static_cast<char*>(obj->device->GetClient()->GetCmdSpace(requiredSize));
                 cmd.Serialize(allocatedBuffer);
 
-                obj->device->{{type.name.camelCase()}}.Free(obj);
+                obj->device->GetClient()->{{type.name.CamelCase()}}Allocator().Free(obj);
             }
 
             void Client{{as_MethodSuffix(type.name, Name("reference"))}}({{cType}} cObj) {
diff --git a/generator/templates/dawn_wire/client/ClientBase.h b/generator/templates/dawn_wire/client/ClientBase.h
new file mode 100644
index 0000000000..fa77852513
--- /dev/null
+++ b/generator/templates/dawn_wire/client/ClientBase.h
@@ -0,0 +1,62 @@
+//* Copyright 2019 The Dawn Authors
+//*
+//* Licensed under the Apache License, Version 2.0 (the "License");
+//* you may not use this file except in compliance with the License.
+//* You may obtain a copy of the License at
+//*
+//*     http://www.apache.org/licenses/LICENSE-2.0
+//*
+//* Unless required by applicable law or agreed to in writing, software
+//* distributed under the License is distributed on an "AS IS" BASIS,
+//* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//* See the License for the specific language governing permissions and
+//* limitations under the License.
+
+#ifndef DAWNWIRE_CLIENT_CLIENTBASE_AUTOGEN_H_
+#define DAWNWIRE_CLIENT_CLIENTBASE_AUTOGEN_H_
+
+#include "dawn_wire/WireCmd_autogen.h"
+#include "dawn_wire/client/ApiObjects.h"
+#include "dawn_wire/client/ObjectAllocator.h"
+
+namespace dawn_wire { namespace client {
+
+    class ClientBase : public ObjectIdProvider {
+      public:
+        ClientBase() {
+        }
+
+        virtual ~ClientBase() {
+        }
+
+        {% for type in by_category["object"] %}
+            const ObjectAllocator<{{type.name.CamelCase()}}>& {{type.name.CamelCase()}}Allocator() const {
+                return m{{type.name.CamelCase()}}Allocator;
+            }
+            ObjectAllocator<{{type.name.CamelCase()}}>& {{type.name.CamelCase()}}Allocator() {
+                return m{{type.name.CamelCase()}}Allocator;
+            }
+        {% endfor %}
+
+      private:
+        // Implementation of the ObjectIdProvider interface
+        {% for type in by_category["object"] %}
+            ObjectId GetId({{as_cType(type.name)}} object) const final {
+                return object == nullptr ? 0 : reinterpret_cast<{{as_wireType(type)}}>(object)->id;
+            }
+            ObjectId GetOptionalId({{as_cType(type.name)}} object) const final {
+                if (object == nullptr) {
+                    return 0;
+                }
+                return GetId(object);
+            }
+        {% endfor %}
+
+        {% for type in by_category["object"] %}
+            ObjectAllocator<{{type.name.CamelCase()}}> m{{type.name.CamelCase()}}Allocator;
+        {% endfor %}
+    };
+
+}}  // namespace dawn_wire::client
+
+#endif  // DAWNWIRE_CLIENT_CLIENTBASE_AUTOGEN_H_
diff --git a/generator/templates/dawn_wire/client/ClientHandlers.cpp b/generator/templates/dawn_wire/client/ClientHandlers.cpp
index 31a8081051..75beddc505 100644
--- a/generator/templates/dawn_wire/client/ClientHandlers.cpp
+++ b/generator/templates/dawn_wire/client/ClientHandlers.cpp
@@ -14,7 +14,6 @@
 
 #include "common/Assert.h"
 #include "dawn_wire/client/Client.h"
-#include "dawn_wire/client/Device_autogen.h"
 
 #include <string>
 
@@ -31,8 +30,8 @@ namespace dawn_wire { namespace client {
 
             DAWN_ASSERT(cmd.message != nullptr);
 
-            auto* builtObject = mDevice->{{type.built_type.name.camelCase()}}.GetObject(cmd.builtObject.id);
-            uint32_t objectSerial = mDevice->{{type.built_type.name.camelCase()}}.GetSerial(cmd.builtObject.id);
+            auto* builtObject = mDevice->GetClient()->{{type.built_type.name.CamelCase()}}Allocator().GetObject(cmd.builtObject.id);
+            uint32_t objectSerial = mDevice->GetClient()->{{type.built_type.name.CamelCase()}}Allocator().GetSerial(cmd.builtObject.id);
 
             //* The object might have been deleted or a new object created with the same ID.
             if (builtObject == nullptr || objectSerial != cmd.builtObject.serial) {
diff --git a/generator/templates/dawn_wire/client/Device.h b/generator/templates/dawn_wire/client/Device.h
deleted file mode 100644
index 796383a3aa..0000000000
--- a/generator/templates/dawn_wire/client/Device.h
+++ /dev/null
@@ -1,73 +0,0 @@
-//* Copyright 2019 The Dawn Authors
-//*
-//* Licensed under the Apache License, Version 2.0 (the "License");
-//* you may not use this file except in compliance with the License.
-//* You may obtain a copy of the License at
-//*
-//*     http://www.apache.org/licenses/LICENSE-2.0
-//*
-//* Unless required by applicable law or agreed to in writing, software
-//* distributed under the License is distributed on an "AS IS" BASIS,
-//* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-//* See the License for the specific language governing permissions and
-//* limitations under the License.
-
-#ifndef DAWNWIRE_CLIENT_DEVICE_AUTOGEN_H_
-#define DAWNWIRE_CLIENT_DEVICE_AUTOGEN_H_
-
-#include <dawn/dawn.h>
-
-#include "dawn_wire/Wire.h"
-#include "dawn_wire/WireCmd_autogen.h"
-#include "dawn_wire/client/ApiObjects.h"
-#include "dawn_wire/client/ObjectAllocator.h"
-
-namespace dawn_wire { namespace client {
-    //* The client wire uses the global Dawn device to store its global data such as the serializer
-    //* and the object id allocators.
-    class Device : public ObjectBase, public ObjectIdProvider {
-        public:
-            Device(CommandSerializer* serializer)
-                : ObjectBase(this, 1, 1),
-                {% for type in by_category["object"] if not type.name.canonical_case() == "device" %}
-                    {{type.name.camelCase()}}(this),
-                {% endfor %}
-                mSerializer(serializer) {
-            }
-
-            void* GetCmdSpace(size_t size) {
-                return mSerializer->GetCmdSpace(size);
-            }
-
-            {% for type in by_category["object"] if not type.name.canonical_case() == "device" %}
-                ObjectAllocator<{{type.name.CamelCase()}}> {{type.name.camelCase()}};
-            {% endfor %}
-
-            // Implementation of the ObjectIdProvider interface
-            {% for type in by_category["object"] %}
-                ObjectId GetId({{as_cType(type.name)}} object) const final {
-                    return reinterpret_cast<{{as_wireType(type)}}>(object)->id;
-                }
-                ObjectId GetOptionalId({{as_cType(type.name)}} object) const final {
-                    if (object == nullptr) {
-                        return 0;
-                    }
-                    return GetId(object);
-                }
-            {% endfor %}
-
-            void HandleError(const char* message) {
-                if (errorCallback) {
-                    errorCallback(message, errorUserdata);
-                }
-            }
-
-            dawnDeviceErrorCallback errorCallback = nullptr;
-            dawnCallbackUserdata errorUserdata;
-
-        private:
-            CommandSerializer* mSerializer = nullptr;
-    };
-}}  // namespace dawn_wire::client
-
-#endif  // DAWNWIRE_CLIENT_DEVICE_AUTOGEN_H_
diff --git a/src/dawn_wire/DawnWire.cpp b/src/dawn_wire/DawnWire.cpp
index 7dca809f92..56792d0b6e 100644
--- a/src/dawn_wire/DawnWire.cpp
+++ b/src/dawn_wire/DawnWire.cpp
@@ -13,19 +13,13 @@
 // limitations under the License.
 
 #include "dawn_wire/client/Client.h"
-#include "dawn_wire/client/Device_autogen.h"
 #include "dawn_wire/server/Server.h"
 
 namespace dawn_wire {
     CommandHandler* NewClientDevice(dawnProcTable* procs,
                                     dawnDevice* device,
                                     CommandSerializer* serializer) {
-        auto clientDevice = new client::Device(serializer);
-
-        *device = reinterpret_cast<dawnDeviceImpl*>(clientDevice);
-        *procs = client::GetProcs();
-
-        return new client::Client(clientDevice);
+        return new client::Client(procs, device, serializer);
     }
 
     CommandHandler* NewServerCommandHandler(dawnDevice device,
diff --git a/src/dawn_wire/client/ApiObjects.h b/src/dawn_wire/client/ApiObjects.h
index c7a52c3cba..b74eefe615 100644
--- a/src/dawn_wire/client/ApiObjects.h
+++ b/src/dawn_wire/client/ApiObjects.h
@@ -18,6 +18,7 @@
 #include "dawn_wire/client/ObjectBase.h"
 
 #include "dawn_wire/client/Buffer.h"
+#include "dawn_wire/client/Device.h"
 #include "dawn_wire/client/Fence.h"
 
 #include "dawn_wire/client/ApiObjects_autogen.h"
diff --git a/src/dawn_wire/client/ApiProcs.cpp b/src/dawn_wire/client/ApiProcs.cpp
index 99f620a61b..d5a4494de9 100644
--- a/src/dawn_wire/client/ApiProcs.cpp
+++ b/src/dawn_wire/client/ApiProcs.cpp
@@ -12,8 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "dawn_wire/client/ApiObjects.h"
 #include "dawn_wire/client/ApiProcs_autogen.h"
-#include "dawn_wire/client/Device_autogen.h"
+#include "dawn_wire/client/Client.h"
 
 namespace dawn_wire { namespace client {
 
@@ -42,7 +43,8 @@ namespace dawn_wire { namespace client {
         cmd.isWrite = false;
 
         size_t requiredSize = cmd.GetRequiredSize();
-        char* allocatedBuffer = static_cast<char*>(buffer->device->GetCmdSpace(requiredSize));
+        char* allocatedBuffer =
+            static_cast<char*>(buffer->device->GetClient()->GetCmdSpace(requiredSize));
         cmd.Serialize(allocatedBuffer);
     }
 
@@ -71,7 +73,8 @@ namespace dawn_wire { namespace client {
         cmd.isWrite = true;
 
         size_t requiredSize = cmd.GetRequiredSize();
-        char* allocatedBuffer = static_cast<char*>(buffer->device->GetCmdSpace(requiredSize));
+        char* allocatedBuffer =
+            static_cast<char*>(buffer->device->GetClient()->GetCmdSpace(requiredSize));
         cmd.Serialize(allocatedBuffer);
     }
 
@@ -124,7 +127,7 @@ namespace dawn_wire { namespace client {
 
                 size_t requiredSize = cmd.GetRequiredSize();
                 char* allocatedBuffer =
-                    static_cast<char*>(buffer->device->GetCmdSpace(requiredSize));
+                    static_cast<char*>(buffer->device->GetClient()->GetCmdSpace(requiredSize));
                 cmd.Serialize(allocatedBuffer);
             }
 
@@ -164,9 +167,8 @@ namespace dawn_wire { namespace client {
     void ClientDeviceSetErrorCallback(dawnDevice cSelf,
                                       dawnDeviceErrorCallback callback,
                                       dawnCallbackUserdata userdata) {
-        Device* self = reinterpret_cast<Device*>(cSelf);
-        self->errorCallback = callback;
-        self->errorUserdata = userdata;
+        Device* device = reinterpret_cast<Device*>(cSelf);
+        device->SetErrorCallback(callback, userdata);
     }
 
 }}  // namespace dawn_wire::client
diff --git a/src/dawn_wire/client/Client.cpp b/src/dawn_wire/client/Client.cpp
index 6921fa9588..ecd332ec94 100644
--- a/src/dawn_wire/client/Client.cpp
+++ b/src/dawn_wire/client/Client.cpp
@@ -13,10 +13,20 @@
 // limitations under the License.
 
 #include "dawn_wire/client/Client.h"
+#include "dawn_wire/client/Device.h"
 
 namespace dawn_wire { namespace client {
 
-    Client::Client(Device* device) : mDevice(device) {
+    Client::Client(dawnProcTable* procs, dawnDevice* device, CommandSerializer* serializer)
+        : ClientBase(),
+          mDevice(DeviceAllocator().New(this)->object.get()),
+          mSerializer(serializer) {
+        *device = reinterpret_cast<dawnDeviceImpl*>(mDevice);
+        *procs = client::GetProcs();
+    }
+
+    Client::~Client() {
+        DeviceAllocator().Free(mDevice);
     }
 
 }}  // namespace dawn_wire::client
diff --git a/src/dawn_wire/client/Client.h b/src/dawn_wire/client/Client.h
index cf975e8b95..3f8a7034ec 100644
--- a/src/dawn_wire/client/Client.h
+++ b/src/dawn_wire/client/Client.h
@@ -19,20 +19,28 @@
 
 #include "dawn_wire/WireCmd_autogen.h"
 #include "dawn_wire/WireDeserializeAllocator.h"
+#include "dawn_wire/client/ClientBase_autogen.h"
 
 namespace dawn_wire { namespace client {
 
     class Device;
 
-    class Client : public CommandHandler {
+    class Client : public ClientBase, public CommandHandler {
       public:
-        Client(Device* device);
+        Client(dawnProcTable* procs, dawnDevice* device, CommandSerializer* serializer);
+        ~Client();
+
         const char* HandleCommands(const char* commands, size_t size);
 
+        void* GetCmdSpace(size_t size) {
+            return mSerializer->GetCmdSpace(size);
+        }
+
       private:
 #include "dawn_wire/client/ClientPrototypes_autogen.inl"
 
-        Device* mDevice;
+        Device* mDevice = nullptr;
+        CommandSerializer* mSerializer = nullptr;
         WireDeserializeAllocator mAllocator;
     };
 
diff --git a/src/dawn_wire/client/ClientHandlers.cpp b/src/dawn_wire/client/ClientHandlers.cpp
index dc64ec2cc2..913b7a5f78 100644
--- a/src/dawn_wire/client/ClientHandlers.cpp
+++ b/src/dawn_wire/client/ClientHandlers.cpp
@@ -14,7 +14,7 @@
 
 #include "common/Assert.h"
 #include "dawn_wire/client/Client.h"
-#include "dawn_wire/client/Device_autogen.h"
+#include "dawn_wire/client/Device.h"
 
 namespace dawn_wire { namespace client {
 
@@ -40,8 +40,8 @@ namespace dawn_wire { namespace client {
             return false;
         }
 
-        auto* buffer = mDevice->buffer.GetObject(cmd.buffer.id);
-        uint32_t bufferSerial = mDevice->buffer.GetSerial(cmd.buffer.id);
+        auto* buffer = mDevice->GetClient()->BufferAllocator().GetObject(cmd.buffer.id);
+        uint32_t bufferSerial = mDevice->GetClient()->BufferAllocator().GetSerial(cmd.buffer.id);
 
         // The buffer might have been deleted or recreated so this isn't an error.
         if (buffer == nullptr || bufferSerial != cmd.buffer.serial) {
@@ -102,8 +102,8 @@ namespace dawn_wire { namespace client {
             return false;
         }
 
-        auto* buffer = mDevice->buffer.GetObject(cmd.buffer.id);
-        uint32_t bufferSerial = mDevice->buffer.GetSerial(cmd.buffer.id);
+        auto* buffer = mDevice->GetClient()->BufferAllocator().GetObject(cmd.buffer.id);
+        uint32_t bufferSerial = mDevice->GetClient()->BufferAllocator().GetSerial(cmd.buffer.id);
 
         // The buffer might have been deleted or recreated so this isn't an error.
         if (buffer == nullptr || bufferSerial != cmd.buffer.serial) {
@@ -156,8 +156,8 @@ namespace dawn_wire { namespace client {
             return false;
         }
 
-        auto* fence = mDevice->fence.GetObject(cmd.fence.id);
-        uint32_t fenceSerial = mDevice->fence.GetSerial(cmd.fence.id);
+        auto* fence = mDevice->GetClient()->FenceAllocator().GetObject(cmd.fence.id);
+        uint32_t fenceSerial = mDevice->GetClient()->FenceAllocator().GetSerial(cmd.fence.id);
 
         // The fence might have been deleted or recreated so this isn't an error.
         if (fence == nullptr || fenceSerial != cmd.fence.serial) {
diff --git a/src/dawn_wire/client/Device.cpp b/src/dawn_wire/client/Device.cpp
new file mode 100644
index 0000000000..57e6e16ba3
--- /dev/null
+++ b/src/dawn_wire/client/Device.cpp
@@ -0,0 +1,40 @@
+// Copyright 2019 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "dawn_wire/client/Device.h"
+
+namespace dawn_wire { namespace client {
+
+    Device::Device(Client* client, uint32_t refcount, uint32_t id)
+        : ObjectBase(this, refcount, id), mClient(client) {
+        this->device = this;
+    }
+
+    Client* Device::GetClient() {
+        return mClient;
+    }
+
+    void Device::HandleError(const char* message) {
+        if (mErrorCallback) {
+            mErrorCallback(message, mErrorUserdata);
+        }
+    }
+
+    void Device::SetErrorCallback(dawnDeviceErrorCallback errorCallback,
+                                  dawnCallbackUserdata errorUserdata) {
+        mErrorCallback = errorCallback;
+        mErrorUserdata = errorUserdata;
+    }
+
+}}  // namespace dawn_wire::client
diff --git a/src/dawn_wire/client/Device.h b/src/dawn_wire/client/Device.h
new file mode 100644
index 0000000000..f3d49d778d
--- /dev/null
+++ b/src/dawn_wire/client/Device.h
@@ -0,0 +1,43 @@
+// Copyright 2019 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef DAWNWIRE_CLIENT_DEVICE_H_
+#define DAWNWIRE_CLIENT_DEVICE_H_
+
+#include <dawn/dawn.h>
+
+#include "dawn_wire/client/ObjectBase.h"
+
+namespace dawn_wire { namespace client {
+
+    class Client;
+
+    class Device : public ObjectBase {
+      public:
+        Device(Client* client, uint32_t refcount, uint32_t id);
+
+        Client* GetClient();
+        void HandleError(const char* message);
+        void SetErrorCallback(dawnDeviceErrorCallback errorCallback,
+                              dawnCallbackUserdata errorUserdata);
+
+      private:
+        Client* mClient = nullptr;
+        dawnDeviceErrorCallback mErrorCallback = nullptr;
+        dawnCallbackUserdata mErrorUserdata;
+    };
+
+}}  // namespace dawn_wire::client
+
+#endif  // DAWNWIRE_CLIENT_DEVICE_H_
diff --git a/src/dawn_wire/client/ObjectAllocator.h b/src/dawn_wire/client/ObjectAllocator.h
index c50307cc1b..3b1b60e6d0 100644
--- a/src/dawn_wire/client/ObjectAllocator.h
+++ b/src/dawn_wire/client/ObjectAllocator.h
@@ -22,12 +22,16 @@
 
 namespace dawn_wire { namespace client {
 
+    class Client;
     class Device;
 
     // TODO(cwallez@chromium.org): Do something with objects before they are destroyed ?
     //  - Call still uncalled builder callbacks
     template <typename T>
     class ObjectAllocator {
+        using ObjectOwner =
+            typename std::conditional<std::is_same<T, Device>::value, Client, Device>::type;
+
       public:
         struct ObjectAndSerial {
             ObjectAndSerial(std::unique_ptr<T> object, uint32_t serial)
@@ -37,14 +41,14 @@ namespace dawn_wire { namespace client {
             uint32_t serial;
         };
 
-        ObjectAllocator(Device* device) : mDevice(device) {
+        ObjectAllocator() {
             // ID 0 is nullptr
             mObjects.emplace_back(nullptr, 0);
         }
 
-        ObjectAndSerial* New() {
+        ObjectAndSerial* New(ObjectOwner* owner) {
             uint32_t id = GetNewId();
-            T* result = new T(mDevice, 1, id);
+            T* result = new T(owner, 1, id);
             auto object = std::unique_ptr<T>(result);
 
             if (id >= mObjects.size()) {
diff --git a/src/tests/unittests/WireTests.cpp b/src/tests/unittests/WireTests.cpp
index 48db4e6a7b..b032fc23ec 100644
--- a/src/tests/unittests/WireTests.cpp
+++ b/src/tests/unittests/WireTests.cpp
@@ -170,6 +170,10 @@ class WireTestsBase : public Test {
         void TearDown() override {
             dawnSetProcs(nullptr);
 
+            // Reset client before mocks are deleted.
+            // Incomplete callbacks will be called on deletion, so the mocks cannot be null.
+            mWireClient = nullptr;
+
             // Delete mocks so that expectations are checked
             mockDeviceErrorCallback = nullptr;
             mockBuilderErrorCallback = nullptr;