diff --git a/cwltool/argparser.py b/cwltool/argparser.py
index 0c4e51f3f..bf0d5c4ee 100644
--- a/cwltool/argparser.py
+++ b/cwltool/argparser.py
@@ -66,7 +66,9 @@ def arg_parser() -> argparse.ArgumentParser:
     env_table.add_env(
         "CWL_SINGULARITY_CACHE",
         f"directory path to find already downloaded Singularity images; "
-        f"[{bt}]dockerFile[/] images will also be searched for and stored here",
+        f"[{bt}]dockerFile[/] images will also be searched for and stored here. "
+        f"Images can be pre-pulled into this directory using "
+        f"[link=https://cwl-utils.readthedocs.io/en/latest/#cwl-docker-extract]cwl-docker-extract[/] from cwl-utils",
     )
     env_table.add_env(
         "ORCID",