diff --git a/Patches.md b/Patches.md
index 5ecd3fd..6fca47c 100644
--- a/Patches.md
+++ b/Patches.md
@@ -15,7 +15,7 @@ Navigate to the `tahoe-lafs` folder and type `git branch` to make sure `master`
 
 Now, hack at Tahoe-LAFS!
 
-Once you think you have solved the issue run the test suite with `python setup.py test`. This ensures that you didn't accidentally break something while working on your patch.
+Once you think you have solved the issue run the test suite with `tox`. This ensures that you didn't accidentally break something while working on your patch.
 
 Now that all of the existing unit tests pass, [write your own tests](https://tahoe-lafs.org/trac/tahoe-lafs/wiki/HowToWriteTests) for the ticket if they don't already exist, and make sure that they pass. Also ensure that `make pyflakes` finds no errors or warnings.