diff --git a/src/modules.cc b/src/modules.cc
index a4ed5e0..6ca704e 100644
--- a/src/modules.cc
+++ b/src/modules.cc
@@ -35,11 +35,13 @@ template<typename T>
 struct COMPAT<T, void_t<decltype(std::declval<T>().user_data_dir.string())>> {
   static std::string get_shared_data_dir() {
     // path::string() returns native encoding on Windows
-    return rime::Service::instance().deployer().shared_data_dir.string();
+    T &deployer = rime::Service::instance().deployer();
+    return deployer.shared_data_dir.string();
   }
 
   static std::string get_user_data_dir() {
-    return rime::Service::instance().deployer().user_data_dir.string();
+    T &deployer = rime::Service::instance().deployer();
+    return deployer.user_data_dir.string();
   }
 };
 }
diff --git a/src/opencc.cc b/src/opencc.cc
index 1cf06c9..4413397 100644
--- a/src/opencc.cc
+++ b/src/opencc.cc
@@ -191,8 +191,9 @@ namespace OpenccReg {
   template<typename U>
   struct COMPAT<U, void_t<decltype(std::declval<U>().user_data_dir.string())>> {
     static optional<T> make(const string &filename) {
-      path user_path = Service::instance().deployer().user_data_dir;
-      path shared_path = Service::instance().deployer().shared_data_dir;
+      U &deployer = Service::instance().deployer();
+      auto user_path = deployer.user_data_dir;
+      auto shared_path = deployer.shared_data_dir;
       try{
         return T((user_path / "opencc" / filename).u8string());
       }
diff --git a/src/types.cc b/src/types.cc
index 877477d..0f38eb4 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -55,19 +55,23 @@ struct COMPAT {
 template<typename T>
 struct COMPAT<T, void_t<decltype(std::declval<T>().user_data_dir.string())>> {
   static an<ReverseDb> new_ReverseDb(const std::string &file) {
-    return New<ReverseDb>(Service::instance().deployer().user_data_dir / file);
+    T &deployer = Service::instance().deployer();
+    return New<ReverseDb>(deployer.user_data_dir / file);
   }
 
   static string get_shared_data_dir() {
-    return Service::instance().deployer().shared_data_dir.string();
+    T &deployer = Service::instance().deployer();
+    return deployer.shared_data_dir.string();
   }
 
   static string get_user_data_dir() {
-    return Service::instance().deployer().user_data_dir.string();
+    T &deployer = Service::instance().deployer();
+    return deployer.user_data_dir.string();
   }
 
   static string get_sync_dir() {
-    return Service::instance().deployer().sync_dir.string();
+    T &deployer = Service::instance().deployer();
+    return deployer.sync_dir.string();
   }
 };
 
diff --git a/src/types_ext.cc b/src/types_ext.cc
index 99e351d..cd8c6ea 100644
--- a/src/types_ext.cc
+++ b/src/types_ext.cc
@@ -275,11 +275,6 @@ namespace UserDbReg{
     return {};
   }
 
-  string file_name(const T& t) {
-    // returns ANSI encoded string on Windows
-    return t.file_path().string();
-  }
-
   bool Open(T &t) { return t.Open(); }
   bool Close(T &t) { return t.Close(); }
   bool OpenReadOnly(T &t) { return t.OpenReadOnly(); }