diff --git a/demo/api/requirements.txt b/demo/api/requirements.txt
index 5f26b9e..71490f2 100644
--- a/demo/api/requirements.txt
+++ b/demo/api/requirements.txt
@@ -26,5 +26,5 @@ tensorboard==1.13.1
 tensorflow==1.13.1
 tensorflow-estimator==1.13.0
 termcolor==1.1.0
-waitress==1.2.1
+waitress==2.1.1
 Werkzeug==0.15.1