diff --git a/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp b/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
index e6cd3b4..1392896 100644
--- a/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
+++ b/camera/provider/2.4/vts/functional/VtsHalCameraProviderV2_4TargetTest.cpp
@@ -101,7 +101,6 @@
 using ResultMetadataQueue = MessageQueue<uint8_t, kSynchronizedReadWrite>;
 using ::android::hidl::manager::V1_0::IServiceManager;
 
-const char *kProviderFQName = "android.hardware.camera.provider@2.4::ICameraProvider";
 const uint32_t kMaxPreviewWidth = 1920;
 const uint32_t kMaxPreviewHeight = 1080;
 const uint32_t kMaxVideoWidth = 4096;
@@ -243,9 +242,7 @@
 
     virtual void HidlTearDown() override { ALOGI("TearDown CameraHidlEnvironment"); }
 
-    virtual void registerTestServices() override {
-        registerTestService("android.hardware.camera.provider", "2.4", "ICameraProvider");
-    }
+    virtual void registerTestServices() override { registerTestService<ICameraProvider>(); }
 
    private:
     CameraHidlEnvironment() {}
@@ -496,7 +493,7 @@
 class CameraHidlTest : public ::testing::VtsHalHidlTargetTestBase {
 public:
  virtual void SetUp() override {
-     string service_name = CameraHidlEnvironment::Instance()->getServiceName(kProviderFQName);
+     string service_name = CameraHidlEnvironment::Instance()->getServiceName<ICameraProvider>();
      ALOGI("get service with name: %s", service_name.c_str());
      mProvider = ::testing::VtsHalHidlTargetTestBase::getService<ICameraProvider>(service_name);
      ASSERT_NE(mProvider, nullptr);
diff --git a/graphics/composer/2.1/vts/functional/VtsHalGraphicsComposerV2_1TargetTest.cpp b/graphics/composer/2.1/vts/functional/VtsHalGraphicsComposerV2_1TargetTest.cpp
index 0f03546..18955da 100644
--- a/graphics/composer/2.1/vts/functional/VtsHalGraphicsComposerV2_1TargetTest.cpp
+++ b/graphics/composer/2.1/vts/functional/VtsHalGraphicsComposerV2_1TargetTest.cpp
@@ -50,21 +50,40 @@
 using android::hardware::graphics::mapper::V2_0::tests::Gralloc;
 using GrallocError = android::hardware::graphics::mapper::V2_0::Error;
 
+// Test environment for graphics.composer
+class GraphicsComposerHidlEnvironment : public ::testing::VtsHalHidlTargetTestEnvBase {
+   public:
+    // get the test environment singleton
+    static GraphicsComposerHidlEnvironment* Instance() {
+        static GraphicsComposerHidlEnvironment* instance = new GraphicsComposerHidlEnvironment;
+        return instance;
+    }
+
+    virtual void registerTestServices() override { registerTestService<IComposer>(); }
+
+   private:
+    GraphicsComposerHidlEnvironment() {}
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(GraphicsComposerHidlEnvironment);
+};
+
 class GraphicsComposerHidlTest : public ::testing::VtsHalHidlTargetTestBase {
  protected:
   void SetUp() override {
-    ASSERT_NO_FATAL_FAILURE(mComposer = std::make_unique<Composer>());
-    ASSERT_NO_FATAL_FAILURE(mComposerClient = mComposer->createClient());
+      ASSERT_NO_FATAL_FAILURE(
+          mComposer = std::make_unique<Composer>(
+              GraphicsComposerHidlEnvironment::Instance()->getServiceName<IComposer>()));
+      ASSERT_NO_FATAL_FAILURE(mComposerClient = mComposer->createClient());
 
-    mComposerCallback = new GraphicsComposerCallback;
-    mComposerClient->registerCallback(mComposerCallback);
+      mComposerCallback = new GraphicsComposerCallback;
+      mComposerClient->registerCallback(mComposerCallback);
 
-    // assume the first display is primary and is never removed
-    mPrimaryDisplay = waitForFirstDisplay();
+      // assume the first display is primary and is never removed
+      mPrimaryDisplay = waitForFirstDisplay();
 
-    // explicitly disable vsync
-    mComposerClient->setVsyncEnabled(mPrimaryDisplay, false);
-    mComposerCallback->setVsyncAllowed(false);
+      // explicitly disable vsync
+      mComposerClient->setVsyncEnabled(mPrimaryDisplay, false);
+      mComposerCallback->setVsyncAllowed(false);
   }
 
   void TearDown() override {
diff --git a/neuralnetworks/1.0/vts/functional/VtsHalNeuralnetworksV1_0TargetTest.cpp b/neuralnetworks/1.0/vts/functional/VtsHalNeuralnetworksV1_0TargetTest.cpp
index 930ddca..84e67cb 100644
--- a/neuralnetworks/1.0/vts/functional/VtsHalNeuralnetworksV1_0TargetTest.cpp
+++ b/neuralnetworks/1.0/vts/functional/VtsHalNeuralnetworksV1_0TargetTest.cpp
@@ -40,15 +40,13 @@
 }
 
 void NeuralnetworksHidlEnvironment::registerTestServices() {
-    registerTestService("android.hardware.neuralnetworks", "1.0", "IDevice");
+    registerTestService<IDevice>();
 }
 
 // The main test class for NEURALNETWORK HIDL HAL.
 void NeuralnetworksHidlTest::SetUp() {
-    std::string instance =
-        NeuralnetworksHidlEnvironment::getInstance()->getServiceName(IDevice::descriptor);
-    LOG(INFO) << "running vts test with instance: " << instance;
-    device = ::testing::VtsHalHidlTargetTestBase::getService<IDevice>(instance);
+    device = ::testing::VtsHalHidlTargetTestBase::getService<IDevice>(
+        NeuralnetworksHidlEnvironment::getInstance());
     ASSERT_NE(nullptr, device.get());
 }