diff --git a/requirements.txt b/requirements.txt
index d702010..2e7aaad 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -33,7 +33,7 @@ tornado==2.4.1
 transaction==1.4.1
 translationstring==1.1
 venusian==1.0a7
-waitress==0.8.2
+waitress==2.1.1
 werkzeug==0.9.4
 wsgiref==0.1.2
 zope.deprecation==4.0.2