diff --git a/src/core/utils.cpp b/src/core/utils.cpp
index 95930c0..f505cfd 100644
--- a/src/core/utils.cpp
+++ b/src/core/utils.cpp
@@ -2,6 +2,7 @@
 
 #include <iomanip>
 #include <numeric>
+#include <codecvt>
 
 std::string formatCentAsEuroString(const int cent, int width)
 {
@@ -21,44 +22,9 @@ std::string formatCentAsEuroString(const int cent, int width)
 }
 
 #ifdef _WIN32
-// UTF-16 -> UTF-8 conversion
-const std::string convert_to_utf8(const std::wstring& utf16_string)
+std::string convertFromUtf16ToUtf8(std::u16string& utf16String)
 {
-    // get length
-    int length =
-        WideCharToMultiByte(CP_UTF8, 0, utf16_string.c_str(), static_cast<int>(utf16_string.size()),
-                            nullptr, 0, nullptr, nullptr);
-    if (!(length > 0))
-        return std::string();
-    else {
-        string result;
-        result.resize(static_cast<std::string::size_type>(length));
-
-        if (WideCharToMultiByte(CP_UTF8, 0, utf16_string.c_str(),
-                                static_cast<int>(utf16_string.size()), &result[0],
-                                static_cast<int>(result.size()), nullptr, nullptr) == 0)
-            throw error("Failure to execute convert_to_utf8: call to WideCharToMultiByte failed.");
-        else
-            return result;
-    }
+   std::string u8_conv = std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t>{}.to_bytes(utf16String); 
+   return u8_conv;
 }
-// UTF-8 -> UTF-16 conversion
-const std::wstring convert_to_utf16(const std::string& utf8_string)
-{
-  // get length
-  int length = MultiByteToWideChar(CP_UTF8, 0, utf8_string.c_str(), static_cast<int>(utf8_string.size()), nullptr, 0);
-  if(!(length > 0))
-    return std::wstring();
-  else
-  {
-    wstring result;
-    result.resize(static_cast<std::string::size_type>(length));
-
-    if(MultiByteToWideChar(CP_UTF8, 0, utf8_string.c_str(), static_cast<int>(utf8_string.size()),
-                           &result[0], static_cast<int>(result.size())) == 0 )
-      throw error("Failure to execute convert_to_utf16: call to MultiByteToWideChar failed.");
-    else
-      return result;
-  }
-}
-#endif
\ No newline at end of file
+#endif
diff --git a/src/core/utils.h b/src/core/utils.h
index 565a257..d3e8e62 100644
--- a/src/core/utils.h
+++ b/src/core/utils.h
@@ -2,16 +2,12 @@
 #define UTILS_H
 
 #include <string>
-
-#ifdef _WIN32
-#include <windows.h>
-#endif
+#include <locale>
 
 std::string formatCentAsEuroString(const int cent, int width = 10);
 
 #ifdef __WIN32
-const std::string convert_to_utf8(const std::wstring& utf16_string);
-const std::wstring convert_to_utf16(const std::string& utf8_string);
+std::string convertFromUtf16ToUtf8(std::u16string& utf16String);
 #endif
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/gui/mainwindow.cpp b/src/gui/mainwindow.cpp
index 29f4efd..5fe2a88 100644
--- a/src/gui/mainwindow.cpp
+++ b/src/gui/mainwindow.cpp
@@ -376,8 +376,8 @@ void MainWindow::onImportSellerExcelActionTriggered()
 
     if (filename.isEmpty())
         return;
-
-    ExcelReader::readSellersFromFile(filename.toStdString(), marketplace_.get());
+    std::u16string fname16 = filename.toStdU16String();
+    ExcelReader::readSellersFromFile(convertFromUtf16ToUtf8(fname16), marketplace_.get());
 }
 
 void MainWindow::onImportSellerJsonActionTriggered()