diff --git a/requirements.txt b/requirements.txt
index 5a6a937..eac1d8b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,3 +15,4 @@ python-dateutil==2.8.1
 six==1.14.0
 soupsieve==1.9.5
 Werkzeug==0.16.0
+waitress==1.4.3