diff --git a/xs/src/libslic3r/PrintExport.hpp b/xs/src/libslic3r/PrintExport.hpp
index 8286b7165..4de12d3c2 100644
--- a/xs/src/libslic3r/PrintExport.hpp
+++ b/xs/src/libslic3r/PrintExport.hpp
@@ -81,8 +81,8 @@ template<class Backend> class Zipper {
 public:
 
     Zipper(const std::string& /*zipfile_path*/) {
-        static_assert(Backend>::value,
-                      "No zipper implementation provided!");
+        // static_assert(Backend>::value,
+        //               "No zipper implementation provided!");
     }
 
     void next_entry(const std::string& /*fname*/) {}
diff --git a/xs/src/libslic3r/SupportMaterial.cpp b/xs/src/libslic3r/SupportMaterial.cpp
index 2bcf597e6..bd1a9f3fb 100644
--- a/xs/src/libslic3r/SupportMaterial.cpp
+++ b/xs/src/libslic3r/SupportMaterial.cpp
@@ -2618,7 +2618,10 @@ void modulate_extrusion_by_overlapping_layers(
                 (fragment_end.is_start ? &polyline.points.front() : &polyline.points.back());
         }
     private:
-        ExtrusionPathFragmentEndPointAccessor& operator=(const ExtrusionPathFragmentEndPointAccessor&) {}
+        ExtrusionPathFragmentEndPointAccessor& operator=(const ExtrusionPathFragmentEndPointAccessor&) {
+            return *this;
+        }
+
         const std::vector<ExtrusionPathFragment> &m_path_fragments;
     };
     const coord_t search_radius = 7;
diff --git a/xs/src/slic3r/GUI/GUI.cpp b/xs/src/slic3r/GUI/GUI.cpp
index 24d459921..e5ed917b3 100644
--- a/xs/src/slic3r/GUI/GUI.cpp
+++ b/xs/src/slic3r/GUI/GUI.cpp
@@ -991,6 +991,12 @@ wxString from_u8(const std::string &str)
 	return wxString::FromUTF8(str.c_str());
 }
 
+std::string into_u8(const wxString &str)
+{
+	auto buffer_utf8 = str.utf8_str();
+	return std::string(buffer_utf8.data());
+}
+
 void set_model_events_from_perl(Model &model,
 							    int event_object_selection_changed,
 							    int event_object_settings_changed,
diff --git a/xs/src/slic3r/GUI/GUI.hpp b/xs/src/slic3r/GUI/GUI.hpp
index 8dfaf42c6..cbf83aa94 100644
--- a/xs/src/slic3r/GUI/GUI.hpp
+++ b/xs/src/slic3r/GUI/GUI.hpp
@@ -217,6 +217,8 @@ int combochecklist_get_flags(wxComboCtrl* comboCtrl);
 wxString	L_str(const std::string &str);
 // Return wxString from std::string in UTF8
 wxString	from_u8(const std::string &str);
+// Return std::string in UTF8 from wxString
+std::string	into_u8(const wxString &str);
 
 void set_model_events_from_perl(Model &model,
 							    int event_object_selection_changed,
diff --git a/xs/src/slic3r/GUI/GUI_Preview.cpp b/xs/src/slic3r/GUI/GUI_Preview.cpp
index 50d404e78..bfc8b5623 100644
--- a/xs/src/slic3r/GUI/GUI_Preview.cpp
+++ b/xs/src/slic3r/GUI/GUI_Preview.cpp
@@ -99,8 +99,9 @@ bool Preview::init(wxNotebook* notebook, DynamicPrintConfig* config, Print* prin
 
     m_combochecklist_features = new wxComboCtrl();
     m_combochecklist_features->Create(this, wxID_ANY, _(L("Feature types")), wxDefaultPosition, wxSize(200, -1), wxCB_READONLY);
-    std::string feature_text = _(L("Feature types"));
-    std::string feature_items = _(L("Perimeter")) + "|" +
+    std::string feature_text = GUI::into_u8(_(L("Feature types")));
+    std::string feature_items = GUI::into_u8(
+        _(L("Perimeter")) + "|" +
         _(L("External perimeter")) + "|" +
         _(L("Overhang perimeter")) + "|" +
         _(L("Internal infill")) + "|" +
@@ -112,7 +113,8 @@ bool Preview::init(wxNotebook* notebook, DynamicPrintConfig* config, Print* prin
         _(L("Support material")) + "|" +
         _(L("Support material interface")) + "|" +
         _(L("Wipe tower")) + "|" +
-        _(L("Custom"));
+        _(L("Custom"))
+    );
     Slic3r::GUI::create_combochecklist(m_combochecklist_features, feature_text, feature_items, true);
 
     m_checkbox_travel = new wxCheckBox(this, wxID_ANY, _(L("Travel")));