diff --git a/Dockerfile b/Dockerfile
index 932bae3..c93d4c9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,6 +8,7 @@ RUN apt-get -yqq update
 RUN apt-get -yqq install python3-pip python3-dev curl gnupg
 RUN curl -sL https://deb.nodesource.com/setup_10.x | bash
 RUN apt-get install -yq nodejs
+RUN apt-get install -yq python3-markupsafe
 
 # copy our application code
 ADD flask-app /opt/flask-app