diff --git a/README.md b/README.md
index 1894124..a50bab0 100644
--- a/README.md
+++ b/README.md
@@ -80,7 +80,7 @@ The popular buildsystems (setuptools, flit, poetry) do support it.
 For projects that specify test requirements using an [`extra`
 provide](https://packaging.python.org/specifications/core-metadata/#provides-extra-multiple-use),
 these can be added using the `-x` flag.
-Multiple extras can be supplied as a comma separated list.
+Multiple extras can be supplied by repeating the flag or as a comma separated list.
 For example, if upstream suggests installing test dependencies with
 `pip install mypackage[testing]`, the test deps would be generated by: