diff --git a/tox.ini b/tox.ini
index 810b76f0c..45bc438b2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -21,7 +21,7 @@ deps =
     du13: docutils==0.13.1
     du14: docutils==0.14
 setenv =
-    PYTHONWARNINGS = all,ignore::ImportWarning:pkgutil,ignore::ImportWarning:importlib._bootstrap,ignore::ImportWarning:importlib._bootstrap_external,ignore::ImportWarning:pytest_cov.plugin,ignore::DeprecationWarning:site,ignore::DeprecationWarning:_pytest.assertion.rewrite,ignore::DeprecationWarning:_pytest.fixtures
+    PYTHONWARNINGS = all,ignore::ImportWarning:pkgutil,ignore::ImportWarning:importlib._bootstrap,ignore::ImportWarning:importlib._bootstrap_external,ignore::ImportWarning:pytest_cov.plugin,ignore::DeprecationWarning:site,ignore::DeprecationWarning:_pytest.assertion.rewrite,ignore::DeprecationWarning:_pytest.fixtures,ignore::DeprecationWarning:distutils
     SPHINX_TEST_TEMPDIR = {envdir}/testbuild
 commands=
     pytest -Wall --durations 25 {posargs}