diff --git a/fastpair/ui/fast_pair/fast_pair_notification_controller_test.cc b/fastpair/ui/fast_pair/fast_pair_notification_controller_test.cc
index 86a40579..997b8aa6 100644
--- a/fastpair/ui/fast_pair/fast_pair_notification_controller_test.cc
+++ b/fastpair/ui/fast_pair/fast_pair_notification_controller_test.cc
@@ -14,16 +14,16 @@
 
 #include "fastpair/ui/fast_pair/fast_pair_notification_controller.h"
 
-#include <memory>
-#include <vector>
 #include <algorithm>
+#include <memory>
 #include <string>
+#include <vector>
 
 #include "gmock/gmock.h"
 #include "protobuf-matchers/protocol-buffer-matchers.h"
 #include "gtest/gtest.h"
 #include "fastpair/repository/device_metadata.h"
-#include "internal/platform/medium_environment.h"
+#include "fastpair/ui/fast_pair/fake_fast_pair_notification_controller_observer.h"
 
 namespace nearby {
 namespace fastpair {
@@ -33,64 +33,29 @@ const int64_t kDeviceId = 10148625;
 const char kModelId[] = "9adb11";
 const char kDeviceName[] = "Pixel Buds Pro";
 
-class FastPairNotificationControllerObserver
-    : public FastPairNotificationController::Observer {
- public:
-  void OnUpdateDevice(const DeviceMetadata& device) override {
-    device_metadata_name_list_.push_back(device.GetDetails().name());
-    on_update_device_count_++;
-  }
-
-  bool CheckDeviceMetadataListContainTestDevice(
-      const std::string& device_name) {
-    auto it = std::find(device_metadata_name_list_.begin(),
-                        device_metadata_name_list_.end(), device_name);
-    return it != device_metadata_name_list_.end();
-  }
-
-  int on_update_device_count() { return on_update_device_count_; }
-
- private:
-  std::vector<std::string> device_metadata_name_list_;
-  int on_update_device_count_ = 0;
-};
-
 class FastPairNotificationControllerTest : public ::testing::Test {
  protected:
-  FastPairNotificationControllerTest() {}
-  ~FastPairNotificationControllerTest() override = default;
-  void SetUp() override {
-    notification_controller_ =
-        std::make_shared<FastPairNotificationController>();
-    notification_controller_obsesrver_ =
-        std::make_unique<FastPairNotificationControllerObserver>();
-    notification_controller_->AddObserver(
-        notification_controller_obsesrver_.get());
+  FastPairNotificationControllerTest() {
+    notification_controller_.AddObserver(&notification_controller_obsesrver_);
   }
 
-  void TearDown() override { env_.Stop(); }
-
   void TriggerOnUpdateDevice(DeviceMetadata& device) {
-    notification_controller_->ShowGuestDiscoveryNotification(device);
+    notification_controller_.ShowGuestDiscoveryNotification(device);
   }
 
-  MediumEnvironment& env_{MediumEnvironment::Instance()};
-  std::shared_ptr<FastPairNotificationController> notification_controller_;
-  std::unique_ptr<FastPairNotificationControllerObserver>
-      notification_controller_obsesrver_;
+  FastPairNotificationController notification_controller_;
+  FakeFastPairNotificationControllerObserver notification_controller_obsesrver_;
 };
 
 TEST_F(FastPairNotificationControllerTest, ShowGuestDiscoveryNotification) {
-  env_.Start();
   proto::GetObservedDeviceResponse response;
   response.mutable_device()->set_id(kDeviceId);
   response.mutable_device()->set_name(kDeviceName);
   DeviceMetadata device_metadata(response);
   TriggerOnUpdateDevice(device_metadata);
   EXPECT_TRUE(notification_controller_obsesrver_
-                  ->CheckDeviceMetadataListContainTestDevice(kDeviceName));
-  EXPECT_EQ(1, notification_controller_obsesrver_->on_update_device_count());
-  env_.Stop();
+                  .CheckDeviceMetadataListContainTestDevice(kDeviceName));
+  EXPECT_EQ(1, notification_controller_obsesrver_.on_update_device_count());
 }
 
 }  // namespace