diff --git a/src/Wideconvert.cpp b/src/Wideconvert.cpp
index 9a41dda..21b6ed2 100644
--- a/src/Wideconvert.cpp
+++ b/src/Wideconvert.cpp
@@ -20,14 +20,32 @@
 
 #include <algorithm>
 
+/*
+ * NOTE: from http://en.cppreference.com/w/c/string/multibyte/mbstowcs
+ *   and from http://en.cppreference.com/w/c/string/multibyte/wcstombs
+ *
+ * As all bounds-checked functions, mbstowcs_s (wcstombs_s) is only
+ * guaranteed to be available if __STDC_LIB_EXT1__ is defined by the
+ * implementation and if the user defines __STDC_WANT_LIB_EXT1__ to
+ * the integer constant 1 before including stdlib.h.
+ */
+#define __STDC_WANT_LIB_EXT1__ 1
+#include <stdlib.h>
+
 #include "Wideconvert.hpp"
 
+// FIXME: use the C++11
+// see: http://stackoverflow.com/a/18374698
+//      http://stackoverflow.com/q/15615136
+//      http://stackoverflow.com/q/24802133
+//      http://en.cppreference.com/w/cpp/header/codecvt
+
 std::wstring LibUSB::Util::StringToWString( const std::string& ns )
 {
-
+#if defined(__STDC_LIB_EXT1__) || defined(_WIN32)
 	size_t bufferSize;
 
-	// first call to wcstombs_s to get the target buffer size
+	// first call to mbstowcs_s to get the target buffer size
 	mbstowcs_s(&bufferSize, NULL, 0, ns.c_str(), ns.size());
 
 	// create target buffer with required size
@@ -39,12 +57,25 @@ std::wstring LibUSB::Util::StringToWString( const std::string& ns )
 	std::wstring result(buffer, bufferSize);
 	delete[] buffer;
 	return result;
+#else
+	// first call to wcstombs to get the target buffer size
+	size_t bufferSize = mbstowcs (NULL, ns.c_str(), 0);
+
+	// create target buffer with required size
+	wchar_t* buffer = new wchar_t[bufferSize];
+
+	// second call to do the actual conversion
+	mbstowcs(buffer, ns.c_str(), bufferSize);
 
+	std::wstring result(buffer, bufferSize);
+	delete[] buffer;
+	return result;
+#endif
 }
 
 std::string LibUSB::Util::WStringToString( const std::wstring& ws )
 {
-
+#if defined(__STDC_LIB_EXT1__) || defined(_WIN32)
 	size_t bufferSize;
 
 	// first call to wcstombs_s to get the target buffer size
@@ -59,5 +90,18 @@ std::string LibUSB::Util::WStringToString( const std::wstring& ws )
 	std::string result(buffer, bufferSize);
 	delete[] buffer;
 	return result;
+#else
+	// first call to wcstombs to get the target buffer size
+	size_t bufferSize = wcstombs(NULL, ws.c_str(), 0);
+
+	// create target buffer with required size
+	char* buffer = new char[bufferSize];
+
+	// second call to do the actual conversion
+	wcstombs(buffer, ws.c_str(), bufferSize);
 
+	std::string result(buffer, bufferSize);
+	delete[] buffer;
+	return result;
+#endif
 }