diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6a421768a..71258ab2c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -78,7 +78,7 @@ For speedier testing, you can also run [pytest](http://pytest.org/) directly on
 
 ```shell
 cd test/mitmproxy/addons
-pytest --looponfail test_anticache.py
+pytest --cov mitmproxy.addons.anticache --cov-report term-missing --looponfail test_anticache.py
 ```
 
 Please ensure that all patches are accompanied by matching changes in the test suite. The project tries to maintain 100%