diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 260ef99458..8c41c88f94 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -1231,7 +1231,8 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
                     if (! config_substitutions.empty())
                         show_substitutions_info(config_substitutions.substitutions, filename.string());
 
-                    this->model.custom_gcode_per_print_z = model.custom_gcode_per_print_z;
+                    if (load_config)
+                        this->model.custom_gcode_per_print_z = model.custom_gcode_per_print_z;
                 }
 
                 if (load_config) {