diff --git a/docs/how-to/develop-on-borgmatic.md b/docs/how-to/develop-on-borgmatic.md
index 9101c68..5a52352 100644
--- a/docs/how-to/develop-on-borgmatic.md
+++ b/docs/how-to/develop-on-borgmatic.md
@@ -62,6 +62,8 @@ following:
 tox -e black
 ```
 
+Note that Black requires at minimum Python 3.6.
+
 And if you get a complaint from the
 [isort](https://github.com/timothycrosley/isort) Python import orderer, you
 can ask isort to order your imports for you:
diff --git a/tox.ini b/tox.ini
index 2d70978..d84b4b0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,7 +19,6 @@ commands =
     flake8 borgmatic tests
 
 [testenv:black]
-basepython = python3.7
 commands =
     black {posargs} .