diff --git a/src/converter/converter_test.cc b/src/converter/converter_test.cc
index ec651285f..351093a91 100644
--- a/src/converter/converter_test.cc
+++ b/src/converter/converter_test.cc
@@ -381,7 +381,9 @@ class ConverterTest : public testing::TestWithTempUserProfile {
   }
 
   std::unique_ptr<Engine> CreateEngineWithMobilePredictor() {
-    return Engine::CreateMobileEngineHelper<testing::MockDataManager>().value();
+    return Engine::CreateMobileEngine(
+               std::make_unique<testing::MockDataManager>())
+        .value();
   }
 
   bool FindCandidateByValue(absl::string_view value,
diff --git a/src/engine/engine.cc b/src/engine/engine.cc
index 210b419c8..1dc62f589 100644
--- a/src/engine/engine.cc
+++ b/src/engine/engine.cc
@@ -62,27 +62,23 @@ namespace mozc {
 absl::StatusOr<std::unique_ptr<Engine>> Engine::CreateDesktopEngine(
     std::unique_ptr<const DataManager> data_manager) {
   constexpr bool kIsMobile = false;
-
-  auto modules = std::make_unique<engine::Modules>();
-  absl::Status modules_status = modules->Init(std::move(data_manager));
-  if (!modules_status.ok()) {
-    return modules_status;
-  }
-
-  return CreateEngine(std::move(modules), kIsMobile);
+  return CreateEngine(std::move(data_manager), kIsMobile);
 }
 
 absl::StatusOr<std::unique_ptr<Engine>> Engine::CreateMobileEngine(
     std::unique_ptr<const DataManager> data_manager) {
   constexpr bool kIsMobile = true;
+  return CreateEngine(std::move(data_manager), kIsMobile);
+}
 
+absl::StatusOr<std::unique_ptr<Engine>> Engine::CreateEngine(
+    std::unique_ptr<const DataManager> data_manager, bool is_mobile) {
   auto modules = std::make_unique<engine::Modules>();
   absl::Status modules_status = modules->Init(std::move(data_manager));
   if (!modules_status.ok()) {
     return modules_status;
   }
-
-  return CreateEngine(std::move(modules), kIsMobile);
+  return CreateEngine(std::move(modules), is_mobile);
 }
 
 absl::StatusOr<std::unique_ptr<Engine>> Engine::CreateEngine(
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 3a59d368a..49cc0d5bc 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -64,24 +64,14 @@ class Engine : public EngineInterface {
   static absl::StatusOr<std::unique_ptr<Engine>> CreateDesktopEngine(
       std::unique_ptr<const DataManager> data_manager);
 
-  // Helper function for the above factory, where data manager is instantiated
-  // by a default constructor.  Intended to be used for OssDataManager etc.
-  template <typename DataManagerType>
-  static absl::StatusOr<std::unique_ptr<Engine>> CreateDesktopEngineHelper() {
-    return CreateDesktopEngine(std::make_unique<const DataManagerType>());
-  }
-
   // Creates an instance with mobile configuration from a data manager.  The
   // ownership of data manager is passed to the engine instance.
   static absl::StatusOr<std::unique_ptr<Engine>> CreateMobileEngine(
       std::unique_ptr<const DataManager> data_manager);
 
-  // Helper function for the above factory, where data manager is instantiated
-  // by a default constructor.  Intended to be used for OssDataManager etc.
-  template <typename DataManagerType>
-  static absl::StatusOr<std::unique_ptr<Engine>> CreateMobileEngineHelper() {
-    return CreateMobileEngine(std::make_unique<const DataManagerType>());
-  }
+  // Creates an instance from a data manager and is_mobile flag.
+  static absl::StatusOr<std::unique_ptr<Engine>> CreateEngine(
+      std::unique_ptr<const DataManager> data_manager, bool is_mobile);
 
   // Creates an instance with the given modules and is_mobile flag.
   static absl::StatusOr<std::unique_ptr<Engine>> CreateEngine(
diff --git a/src/engine/mock_data_engine_factory.cc b/src/engine/mock_data_engine_factory.cc
index 8e885d22a..b233b5892 100644
--- a/src/engine/mock_data_engine_factory.cc
+++ b/src/engine/mock_data_engine_factory.cc
@@ -38,7 +38,8 @@
 namespace mozc {
 
 absl::StatusOr<std::unique_ptr<Engine>> MockDataEngineFactory::Create() {
-  return Engine::CreateDesktopEngineHelper<mozc::testing::MockDataManager>();
+  return Engine::CreateDesktopEngine(
+      std::make_unique<mozc::testing::MockDataManager>());
 }
 
 }  // namespace mozc
diff --git a/src/engine/oss_engine_factory.h b/src/engine/oss_engine_factory.h
index 36263343d..ba6aa24cb 100644
--- a/src/engine/oss_engine_factory.h
+++ b/src/engine/oss_engine_factory.h
@@ -44,9 +44,9 @@ class OssEngineFactory {
  public:
   static absl::StatusOr<std::unique_ptr<Engine>> Create() {
 #ifdef __ANDROID__
-    return Engine::CreateMobileEngineHelper<oss::OssDataManager>();
+    return Engine::CreateMobileEngine(std::make_unique<oss::OssDataManager>());
 #else   // __ANDROID__
-    return Engine::CreateDesktopEngineHelper<oss::OssDataManager>();
+    return Engine::CreateDesktopEngine(std::make_unique<oss::OssDataManager>());
 #endif  // __ANDROID__
   }
 };