diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 923e9068..768f2a36 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -6,6 +6,10 @@
 #include <spdlog/tweakme.h>
 #include <spdlog/details/null_mutex.h>
 
+#ifdef _WIN32
+#include <spdlog/details/windows_include.h>
+#endif
+
 #include <atomic>
 #include <chrono>
 #include <initializer_list>
@@ -88,9 +92,15 @@ class sink;
 
 #if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
 using filename_t = std::wstring;
+using win32_find_data = WIN32_FIND_DATAW;
+#define find_first_file  FindFirstFileW
+#define find_next_file  FindNextFileW
 #define SPDLOG_FILENAME_T(s) L##s
 #else
 using filename_t = std::string;
+using win32_find_data = WIN32_FIND_DATAA;
+#define find_first_file  FindFirstFileA
+#define find_next_file  FindNextFileA
 #define SPDLOG_FILENAME_T(s) s
 #endif
 
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index 230c6ebf..e0b1de4e 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -554,51 +554,20 @@ std::string SPDLOG_INLINE getenv(const char *field)
 }
 
 #ifdef _WIN32
-#ifdef SPDLOG_WCHAR_FILENAMES
-SPDLOG_INLINE std::vector<std::wstring> get_directory_files(const std::wstring &directory) SPDLOG_NOEXCEPT
-{
-    std::vector<std::wstring> files;
-
-    HANDLE dir;
-    WIN32_FIND_DATAW file_data;
-
-    if ((dir = FindFirstFileW((directory + L"/*").c_str(), &file_data)) == INVALID_HANDLE_VALUE)
-        return files;
-
-    do
-    {
-        const std::wstring file_name = file_data.cFileName;
-        const std::wstring full_file_name = directory + L"/" + file_name;
-        const bool is_directory = (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
-
-        if (file_name[0] == '.')
-            continue;
-
-        if (is_directory)
-            continue;
-
-        files.push_back(full_file_name);
-    } while (FindNextFileW(dir, &file_data));
-
-    FindClose(dir);
-
-    return files;
-}
-#else
-SPDLOG_INLINE std::vector<std::string> get_directory_files(const std::string &directory) SPDLOG_NOEXCEPT
+SPDLOG_INLINE std::vector<filename_t> get_directory_files(const filename_t &directory) SPDLOG_NOEXCEPT
 {
-    std::vector<std::string> files;
+    std::vector<filename_t> files;
 
     HANDLE dir;
-    WIN32_FIND_DATAA file_data;
+    win32_find_data file_data;
 
-    if ((dir = FindFirstFileA((directory + "/*").c_str(), &file_data)) == INVALID_HANDLE_VALUE)
+    if ((dir = find_first_file((directory + SPDLOG_FILENAME_T("/*")).c_str(), &file_data)) == INVALID_HANDLE_VALUE)
         return files;
 
     do
     {
-        const std::string file_name = file_data.cFileName;
-        const std::string full_file_name = directory + "/" + file_name;
+        const filename_t file_name = file_data.cFileName;
+        const filename_t full_file_name = directory + SPDLOG_FILENAME_T("/") + file_name;
         const bool is_directory = (file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
 
         if (file_name[0] == '.')
@@ -608,13 +577,12 @@ SPDLOG_INLINE std::vector<std::string> get_directory_files(const std::string &di
             continue;
 
         files.push_back(full_file_name);
-    } while (FindNextFileA(dir, &file_data));
+    } while (find_next_file(dir, &file_data));
 
     FindClose(dir);
 
     return files;
 }
-#endif
 #else
 SPDLOG_INLINE std::vector<std::string> get_directory_files(const std::string &directory) SPDLOG_NOEXCEPT
 {
diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index 937e5b67..c7d23f69 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -102,11 +102,7 @@ SPDLOG_API bool create_dir(filename_t path);
 // return empty string if field not found
 SPDLOG_API std::string getenv(const char *field);
 
-#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
-SPDLOG_API std::vector<std::wstring> get_directory_files(const std::wstring &directory) SPDLOG_NOEXCEPT;
-#else
-SPDLOG_API std::vector<std::string> get_directory_files(const std::string &directory) SPDLOG_NOEXCEPT;
-#endif
+SPDLOG_API std::vector<filename_t> get_directory_files(const filename_t &directory) SPDLOG_NOEXCEPT;
 
 } // namespace os
 } // namespace details