diff --git a/examples/web_demo/requirements.txt b/examples/web_demo/requirements.txt
index 8fb1d2ccbb2..43e1b98cc34 100644
--- a/examples/web_demo/requirements.txt
+++ b/examples/web_demo/requirements.txt
@@ -4,3 +4,4 @@ tornado
 numpy
 pandas
 pillow
+pyyaml