diff --git a/dash-heroku-master/requirements.txt b/dash-heroku-master/requirements.txt
index a61c9df..2ef38e7 100644
--- a/dash-heroku-master/requirements.txt
+++ b/dash-heroku-master/requirements.txt
@@ -156,7 +156,7 @@ pytz==2019.2
 PyWavelets==1.0.3
 pywin32==224
 pywinpty==0.5.5
-PyYAML==5.1.2
+PyYAML==5.4
 pyzmq==18.1.0
 qtconsole==4.5.4
 requests==2.22.0