diff --git a/requirements.txt b/requirements.txt
index ed8c692..92b37b5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,5 +13,5 @@ scikit-learn==0.21.2
 scipy==1.3.1
 six==1.12.0
 ujson==1.35
-waitress==1.4.1
+waitress==2.1.1
 ZigZag==0.2.2
\ No newline at end of file