diff --git a/dbus_test_utils.h b/dbus_test_utils.h
new file mode 100644
index 0000000..99e6d5e
--- /dev/null
+++ b/dbus_test_utils.h
@@ -0,0 +1,77 @@
+// Copyright 2015 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UPDATE_ENGINE_DBUS_TEST_UTILS_H_
+#define UPDATE_ENGINE_DBUS_TEST_UTILS_H_
+
+#include <set>
+#include <string>
+
+#include <base/bind.h>
+#include <chromeos/message_loops/message_loop.h>
+#include <gmock/gmock.h>
+
+namespace chromeos_update_engine {
+namespace dbus_test_utils {
+
+#define MOCK_SIGNAL_HANDLER_EXPECT_SIGNAL_HANDLER(                           \
+    mock_signal_handler, mock_proxy, signal)                                 \
+  do {                                                                       \
+    EXPECT_CALL((mock_proxy),                                                \
+                Register##signal##SignalHandler(::testing::_, ::testing::_)) \
+        .WillOnce(::chromeos_update_engine::dbus_test_utils::GrabCallbacks(  \
+            &(mock_signal_handler)));                                        \
+  } while (false)
+
+template <typename T>
+class MockSignalHandler {
+ public:
+  MockSignalHandler() = default;
+  ~MockSignalHandler() {
+    if (callback_connected_task_ != chromeos::MessageLoop::kTaskIdNull)
+      chromeos::MessageLoop::current()->CancelTask(callback_connected_task_);
+  }
+
+  // Returns whether the signal handler is registered.
+  bool IsHandlerRegistered() const { return signal_callback_ != nullptr; }
+
+  const base::Callback<T>& signal_callback() { return *signal_callback_.get(); }
+
+  void GrabCallbacks(
+      const base::Callback<T>& signal_callback,
+      dbus::ObjectProxy::OnConnectedCallback on_connected_callback) {
+    signal_callback_.reset(new base::Callback<T>(signal_callback));
+    on_connected_callback_.reset(
+        new dbus::ObjectProxy::OnConnectedCallback(on_connected_callback));
+    // Notify from the main loop that the callback was connected.
+    callback_connected_task_ = chromeos::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(&MockSignalHandler<T>::OnCallbackConnected,
+                   base::Unretained(this)));
+  }
+
+ private:
+  void OnCallbackConnected() {
+    callback_connected_task_ = chromeos::MessageLoop::kTaskIdNull;
+    on_connected_callback_->Run("", "", true);
+  }
+
+  chromeos::MessageLoop::TaskId callback_connected_task_{
+      chromeos::MessageLoop::kTaskIdNull};
+
+  std::unique_ptr<base::Callback<T>> signal_callback_;
+  std::unique_ptr<dbus::ObjectProxy::OnConnectedCallback>
+      on_connected_callback_;
+};
+
+// Defines the action that will call MockSignalHandler<T>::GrabCallbacks for the
+// right type.
+ACTION_P(GrabCallbacks, mock_signal_handler) {
+  mock_signal_handler->GrabCallbacks(arg0, arg1);
+}
+
+}  // namespace dbus_test_utils
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_DBUS_TEST_UTILS_H_