diff --git a/build/docker/ubuntu-xenial/Dockerfile b/build/docker/ubuntu-xenial/Dockerfile
index c640bd9..02b5ac2 100644
--- a/build/docker/ubuntu-xenial/Dockerfile
+++ b/build/docker/ubuntu-xenial/Dockerfile
@@ -197,7 +197,7 @@
       php7.0-dev \
       php-pear \
       re2c \
-      phpunit
+      composer
 
 RUN apt-get install -y --no-install-recommends \
 `# Python dependencies` \