diff --git a/docker/moodle/Dockerfile b/docker/moodle/Dockerfile
index e6f7663..3d46e58 100644
--- a/docker/moodle/Dockerfile
+++ b/docker/moodle/Dockerfile
@@ -22,3 +22,4 @@ RUN echo "group=nobody" >> /etc/php7/php-fpm.d/www.conf
 RUN apk add --no-cache dcron libcap && \
     chown nobody:nobody /usr/sbin/crond && \
     setcap cap_setgid=ep /usr/sbin/crond
+RUN apk add php7-sodium