diff --git a/requirements.txt b/requirements.txt
index bac6f40..b7eea55 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,7 +14,7 @@ six==1.14.0
 translationstring==1.3
 urllib3==1.25.8
 venusian==3.0.0
-waitress==1.4.3
+waitress==2.1.1
 WebOb==1.8.6
 zope.deprecation==4.4.0
 zope.interface==5.1.0