diff --git a/docker/MON/Dockerfile b/docker/MON/Dockerfile
index 96e1633..72eec87 100644
--- a/docker/MON/Dockerfile
+++ b/docker/MON/Dockerfile
@@ -40,7 +40,7 @@
     && rm -rf /var/lib/apt/lists/* \
     && pip3 install pip==9.0.3
 
-RUN pip3 install juju
+RUN pip3 install juju 'pyyaml>=5.1.2'
 
 ARG REPOSITORY_BASE=http://osm-download.etsi.org/repository/osm/debian
 ARG RELEASE=ReleaseFOUR-daily