diff --git a/notebooks/CBAC/requirements.txt b/notebooks/CBAC/requirements.txt
index b73ac1a..a81009f 100644
--- a/notebooks/CBAC/requirements.txt
+++ b/notebooks/CBAC/requirements.txt
@@ -59,7 +59,7 @@ python-dateutil==2.6.1
 python-editor==1.0.3
 python-oauth2==1.0.1
 pytz==2018.5
-PyYAML==3.12
+PyYAML==5.4
 pyzmq==17.0.0
 requests==2.18.4
 retrying==1.3.3