diff --git a/docker/build.sh b/docker/build.sh
index c4ba8d1..85c5aca 100755
--- a/docker/build.sh
+++ b/docker/build.sh
@@ -78,7 +78,7 @@ section_end
 section_start "Push instructions"
 echo "All done. Image ${NAMESPACE}/domserver:${VERSION} and ${NAMESPACE}/judgehost:${VERSION} created"
 echo "If you are a DOMjudge maintainer with access to the domjudge organization on Docker Hub, you can now run the following command to push them to Docker Hub:"
-echo "$ docker push ${NAMESPACE}/domserver:${VERSION} && docker push ${NAMESPACE}/judgehost:${VERSION} && docker push $NAMESPACE}/default-judgehost-chroot:${VERSION}"
+echo "$ docker push ${NAMESPACE}/domserver:${VERSION} && docker push ${NAMESPACE}/judgehost:${VERSION} && docker push ${NAMESPACE}/default-judgehost-chroot:${VERSION}"
 echo "If this is the latest release, also run the following command:"
 echo "$ docker tag ${NAMESPACE}/domserver:${VERSION} ${NAMESPACE}/domserver:latest && \
 docker tag ${NAMESPACE}/judgehost:${VERSION} ${NAMESPACE}/judgehost:latest && \
diff --git a/docker/domserver/Dockerfile b/docker/domserver/Dockerfile
index 3a06f14..d14f16d 100644
--- a/docker/domserver/Dockerfile
+++ b/docker/domserver/Dockerfile
@@ -8,7 +8,7 @@ RUN apt-get update \
 	&& apt-get install --no-install-recommends --no-install-suggests -y \
 	autoconf automake git pkg-config \
 	gcc g++ make acl zip unzip \
-	php-cli php-zip \
+	php-cli php-zip php-bcmath \
 	php-gd php-curl php-mysql php-json php-intl \
 	php-gmp php-xml php-mbstring \
 	sudo bsdmainutils ntp libcgroup-dev procps \