diff --git a/dev-requirements.txt b/dev-requirements.txt
index 053148f..3ab2397 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1 +1,3 @@
+# https://github.com/pypa/virtualenv/issues/1963
+virtualenv!=20.0.32;python_version=="3.4"
 tox