diff --git a/src/slic3r/GUI/PresetComboBoxes.cpp b/src/slic3r/GUI/PresetComboBoxes.cpp
index c4de3d199..d2df49178 100644
--- a/src/slic3r/GUI/PresetComboBoxes.cpp
+++ b/src/slic3r/GUI/PresetComboBoxes.cpp
@@ -417,6 +417,8 @@ void PresetComboBox::add_connected_printers(std::string selected, bool alias_nam
     m_first_printer_idx = GetCount();
     for (auto iter = machine_list.begin(); iter != machine_list.end(); ++iter) {
         Preset* printer_preset = get_printer_preset(iter->second);
+        if (!printer_preset)
+            continue;
         printer_preset->is_visible = true;
         int item_id = Append(from_u8(iter->second->dev_name), wxNullBitmap, &m_first_printer_idx + std::distance(machine_list.begin(), iter));
     }