diff --git a/demo/api/requirements.txt b/demo/api/requirements.txt
index 5f26b9e..0d5164b 100644
--- a/demo/api/requirements.txt
+++ b/demo/api/requirements.txt
@@ -18,7 +18,7 @@ nltk==3.4
 numpy==1.16.2
 pbr==5.1.3
 protobuf==3.7.0
-PyYAML==5.1
+PyYAML==5.4
 scipy==1.2.1
 singledispatch==3.4.0.3
 six==1.12.0