diff --git a/pyramid/requirements.txt b/pyramid/requirements.txt
index c1aea70..771bc3b 100644
--- a/pyramid/requirements.txt
+++ b/pyramid/requirements.txt
@@ -6,7 +6,7 @@ plaster-pastedeploy==0.7
 pyramid==1.10.4
 translationstring==1.3
 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