diff --git a/sago/platform_folders.cpp b/sago/platform_folders.cpp
index 1c9b99c..c797177 100644
--- a/sago/platform_folders.cpp
+++ b/sago/platform_folders.cpp
@@ -80,6 +80,9 @@ static std::string getHome() {
 // For SHGetFolderPathW and various CSIDL "magic numbers"
 #include <shlobj.h>
 
+namespace sago {
+namespace internal {
+
 static std::string win32_utf16_to_utf8(const wchar_t* wstr) {
 	std::string res;
 	// If the 6th parameter is 0 then WideCharToMultiByte returns the number of bytes needed to store the result.
@@ -98,6 +101,9 @@ static std::string win32_utf16_to_utf8(const wchar_t* wstr) {
 	return res;
 }
 
+}  // namesapce internal
+}  // namespace sago
+
 class FreeCoTaskMemory {
 	LPWSTR pointer = NULL;
 public:
@@ -116,7 +122,7 @@ static std::string GetKnownWindowsFolder(REFKNOWNFOLDERID folderId, const char* 
 	if (!SUCCEEDED(hr)) {
 		throw std::runtime_error(errorMsg);
 	}
-	return win32_utf16_to_utf8(wszPath);
+	return sago::internal::win32_utf16_to_utf8(wszPath);
 }
 
 static std::string GetAppData() {
diff --git a/sago/platform_folders.h b/sago/platform_folders.h
index fc9dd3b..a9a6477 100644
--- a/sago/platform_folders.h
+++ b/sago/platform_folders.h
@@ -42,6 +42,9 @@ namespace internal {
 	#if !defined(_WIN32) && !defined(__APPLE__)
 	void appendExtraFoldersTokenizer(const char* envName, const char* envValue, std::vector<std::string>& folders);
 	#endif
+	#ifdef _WIN32
+	std::string win32_utf16_to_utf8(const wchar_t* wstr);
+	#endif
 }
 #endif  //DOXYGEN_SHOULD_SKIP_THIS