diff --git a/tox.ini b/tox.ini
index f338dd9a..7b0bbb36 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,7 @@
 [tox]
 envlist = py{27,36,37,38,39,310,311,312,py,py3},flake8,docs,headers
 skip_missing_interpreters = true
+requires = virtualenv<20.22.0
 
 [testenv]
 deps = pytest