diff --git a/Python3.md b/Python3.md
index 083bff3..37d9daa 100644
--- a/Python3.md
+++ b/Python3.md
@@ -12,8 +12,9 @@ We use [tox](https://tox.readthedocs.io/en/latest/) to standardize environments
 
 1. Install tox (globally, probably; consider [pipx](https://pipxproject.github.io/pipx/)).
 2. In your Tahoe-LAFS working copy, run `tox -e py36 --notest` to bootstrap the `py36` virtualenv.
-3. Activate the environment with `source .tox/py36/bin/activate` or equivalent and run `trial allmydata.test.test_python3` as a smoke test.
-4. `deactivate` the virtualenv (or switch shells) and run `tox -e py36` to exercise the whole suite.
+3. Activate the environment with `source .tox/py36/bin/activate` or equivalent and wire up for local dev with `pip install -e .`
+4. Run `trial allmydata.test.test_python3` as a smoke test.
+5. `deactivate` the virtualenv (or switch shells) and run `tox -e py36` to exercise the whole suite.
 
 ## How to choose a module to port