diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 5fde4b961..a4ee45e6a 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -288,7 +288,7 @@ Other ways to run the tests:
 You can also see the latest test results on `Linux`_ and on `Windows`_.
 
 Note, if you are on Windows and are seeing errors running tox, it may be related to `this issue`_,
-in which case you may have to install tox v3.8.3 e.g. ``python -m pip install tox=3.8.3``
+in which case you may have to install tox v3.8.3 e.g. ``python -m pip install tox==3.8.3``
 
 .. _this issue: https://github.com/tox-dev/tox/issues/1550