diff --git a/requirements.txt b/requirements.txt
index e6f20f8..089b499 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -54,7 +54,7 @@ transaction==2.2.1
 translationstring==1.3
 urllib3==1.22
 venusian==1.1.0
-waitress==1.1.0
+waitress==2.1.1
 webencodings==0.5.1
 WebOb==1.8.1
 WebTest==2.0.29