diff --git a/requirements-dev.txt b/requirements-dev.txt
index 51d70bd..949df95 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -13,4 +13,4 @@ pyflakes==1.6.0
 pytest==3.6.0
 six==1.11.0
 tox==3.0.0
-virtualenv==16.0.0
+virtualenv==20.26.6