diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 496de1d54..4d98fe33b 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -274,7 +274,7 @@ void GLCanvas3D::LayersEditing::render_overlay(const GLCanvas3D& canvas) const
     if (ImGui::IsItemHovered())
     {
         ImGui::BeginTooltip();
-        ImGui::TextUnformatted(_(L("Higher print quality versus higher print speed.")));
+        ImGui::TextUnformatted(_(L("Higher print quality versus higher print speed.")).ToUTF8());
         ImGui::EndTooltip();
     }
 
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index 3f82c43e4..d3d9e61a2 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -603,7 +603,7 @@ void apply_extruder_selector(wxBitmapComboBox** ctrl,
             ++i;
         }
 
-        (*ctrl)->Append(use_full_item_name ? wxString::Format("%s %d", str, i) : std::to_string(i), *bmp);
+        (*ctrl)->Append(use_full_item_name ? wxString::Format("%s %d", str, i) : wxString::Format("%d", i), *bmp);
         ++i;
     }
     (*ctrl)->SetSelection(0);