diff --git a/tox.ini b/tox.ini
index b2974332..3270f10a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -135,19 +135,6 @@ setenv =
     ans12: MITOGEN_TEST_DISTRO_SPECS=debian11-py3 ubuntu2004-py3
     # Ansible 13 (ansible-core 2.20) requires Python >= 3.9 on targets
     ans13: MITOGEN_TEST_DISTRO_SPECS=debian11-py3
-    distros_centos: MITOGEN_TEST_DISTRO_SPECS=centos6 centos7 centos8-py3
-    distros_centos5: MITOGEN_TEST_DISTRO_SPECS=centos5
-    distros_centos6: MITOGEN_TEST_DISTRO_SPECS=centos6
-    distros_centos7: MITOGEN_TEST_DISTRO_SPECS=centos7
-    distros_centos8: MITOGEN_TEST_DISTRO_SPECS=centos8-py3
-    distros_debian: MITOGEN_TEST_DISTRO_SPECS=debian9 debian10 debian11
-    distros_debian9: MITOGEN_TEST_DISTRO_SPECS=debian9
-    distros_debian10: MITOGEN_TEST_DISTRO_SPECS=debian10
-    distros_debian11: MITOGEN_TEST_DISTRO_SPECS=debian11
-    distros_ubuntu: MITOGEN_TEST_DISTRO_SPECS=ubuntu1604 ubuntu1804 ubuntu2004
-    distros_ubuntu1604: MITOGEN_TEST_DISTRO_SPECS=ubuntu1604
-    distros_ubuntu1804: MITOGEN_TEST_DISTRO_SPECS=ubuntu1804
-    distros_ubuntu2004: MITOGEN_TEST_DISTRO_SPECS=ubuntu2004
     m_ans: MODE=ansible
     m_ans: ANSIBLE_SKIP_TAGS=resource_intensive
     m_ans: ANSIBLE_CALLBACK_WHITELIST=profile_tasks