diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 036b6d50b..a9bfb01fa 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -4024,7 +4024,9 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
                 if (boost::iends_with(path.string(), ".stp") ||
                     boost::iends_with(path.string(), ".step")) {
                         double linear = string_to_double_decimal_point(wxGetApp().app_config->get("linear_defletion"));
+                        if (linear <= 0) linear = 0.003;
                         double angle = string_to_double_decimal_point(wxGetApp().app_config->get("angle_defletion"));
+                        if (angle <= 0) angle = 0.5;
                         model = Slic3r::Model:: read_from_step(path.string(), strategy,
                         [this, &dlg, real_filename, &progress_percent, &file_percent, step_percent, INPUT_FILES_RATIO, total_files, i](int load_stage, int current, int total, bool &cancel)
                         {