diff --git a/src/slic3r/GUI/PresetComboBoxes.cpp b/src/slic3r/GUI/PresetComboBoxes.cpp
index 5db374aff..f6ea0f994 100644
--- a/src/slic3r/GUI/PresetComboBoxes.cpp
+++ b/src/slic3r/GUI/PresetComboBoxes.cpp
@@ -500,7 +500,7 @@ void PresetComboBox::add_ams_filaments(std::string selected, bool alias_name)
 {
     bool is_bbl_vendor_preset = m_preset_bundle->printers.get_edited_preset().is_bbl_vendor_preset(m_preset_bundle);
     if (is_bbl_vendor_preset && !m_preset_bundle->filament_ams_list.empty()) {
-        bool dual_extruder   = (--m_preset_bundle->filament_ams_list.end())->first & 0x10000;
+        bool dual_extruder = (m_preset_bundle->filament_ams_list.begin()->first & 0x10000) == 0;
         set_label_marker(Append(separator(dual_extruder ? L("Left filaments") : L("AMS filaments")), wxNullBitmap));
         m_first_ams_filament = GetCount();
         auto &filaments      = m_collection->get_presets();