diff --git a/Dockerfile b/Dockerfile
index 89d9526d6ad94bc183af3ff158248fcea425d1de..b5ae2953705ac1c587fb854e9d0dcbff0797b761 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,7 +20,7 @@ RUN apk update && \
     apk add --no-cache bash python nodejs git unzip \
         php7 php7-phar php7-json php7-dom php7-gd php7-mbstring php7-openssl \
         php7-pdo php7-curl php7-xml php7-zip php7-session php7-ctype \
-        php7-tokenizer php7-simplexml && \
+        php7-tokenizer php7-simplexml php7-xmlwriter && \
     ln -s /usr/bin/php7 /usr/local/bin/php &&\
     \
     wget -q https://github.com/docker/compose/releases/download/${compose_version}/docker-compose-`uname -s`-`uname -m` -O /usr/local/bin/docker-compose && \