diff --git a/esp_idf_size/main.py b/esp_idf_size/main.py
index a600b90..cfe3618 100644
--- a/esp_idf_size/main.py
+++ b/esp_idf_size/main.py
@@ -45,6 +45,8 @@ def main() -> None:
     parser = argparse.ArgumentParser(prog='esp_idf_size',
                                      description='This tool displays firmware size information for project built by ESP-IDF')
 
+    parser.add_argument('--ng', action='store_true', help="stub for 1.x compat")
+
     parser.add_argument('input_file',
                         metavar='MAP_FILE',
                         help='Path to the link map file generated by the ESP-IDF build system.')