diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 203ba175af..426454bfac 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -4765,7 +4765,7 @@ wxString Plater::priv::get_export_file(GUI::FileType file_type)
     wxString out_path = dlg.GetPath();
     fs::path path(into_path(out_path));
 #ifdef __WXMSW__
-    if (path.extension() != output_file.extension()) {
+    if (boost::iequals(path.extension().string(), output_file.extension().string()) == false) {
         out_path += output_file.extension().string();
         boost::system::error_code ec;
         if (boost::filesystem::exists(into_u8(out_path), ec)) {
@@ -10848,7 +10848,7 @@ bool Plater::load_files(const wxArrayString& filenames)
 
     case LoadFilesType::Multiple3MFOther:
         for (const auto &path : normal_paths) {
-            if (wxString(encode_path(path.filename().string().c_str())).EndsWith("3mf")) {
+            if (boost::iends_with(path.filename().string(), ".3mf")){
                 if (first_file.size() <= 0)
                     first_file.push_back(path);
                 else
@@ -10928,7 +10928,9 @@ int Plater::get_3mf_file_count(std::vector<fs::path> paths)
 {
     auto count = 0;
     for (const auto &path : paths) {
-        if (wxString(encode_path(path.filename().string().c_str())).EndsWith("3mf")) count++;
+        if (boost::iends_with(path.filename().string(), ".3mf")) {
+            count++;
+        }
     }
     return count;
 }
@@ -11007,7 +11009,7 @@ void Plater::add_file()
     }
     case LoadFilesType::Multiple3MFOther:
         for (const auto &path : paths) {
-            if (wxString(encode_path(path.filename().string().c_str())).EndsWith("3mf")) {
+            if (boost::iends_with(path.filename().string(), ".3mf")) {
                 if (first_file.size() <= 0)
                     first_file.push_back(path);
                 else