diff --git a/ci_container/Dockerfile b/ci_container/Dockerfile
new file mode 100644
index 0000000..5989691
--- /dev/null
+++ b/ci_container/Dockerfile
@@ -0,0 +1,29 @@
+FROM debian:latest
+
+RUN apt-get update; \
+    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
+        build-essential \
+        exim4-daemon-heavy \
+        exim4-dev \
+        gcovr \
+        git \
+        libsodium-dev \
+        openssl \
+        pkg-config \
+        python3-pip \
+        libxml2-utils; \
+    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
+        debhelper \
+        debsigs \
+        devscripts \
+        dh-make \
+        git-buildpackage \
+        gpgv1 \
+        meson; \
+    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
+        vim; \
+    DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get clean; \
+    rm -rf /var/lib/apt/lists/*;
+
+RUN pip3 install --upgrade meson ninja; \
+    rm -rf ~/.cache/pip/*;
diff --git a/ci_container/build.sh b/ci_container/build.sh
index 002285a..cd65a76 100755
--- a/ci_container/build.sh
+++ b/ci_container/build.sh
@@ -29,7 +29,15 @@ while getopts "r:u:p:b:t:" OPTION; do
             TAG="${OPTARG}"
             ;;
         *)
-            echo "Invalid argument"
+            echo "Usage: $0 [OPTIONS]"
+	    echo
+	    echo "Options:"
+	    echo "  -r <registry> (default: \"${REGISTRY}\")"
+	    echo "  -u <username> (default: \"${USERNAME}\")"
+	    echo "  -p <password> (default: \"${PASSWORD}\")"
+	    echo "  -b <basename> (default: \"${BASENAME}\")"
+	    echo "  -t <tag>      (default: \"${TAG}\")"
+	    echo
             exit 127
     esac
 done
@@ -47,39 +55,21 @@ for i in "${images[@]}"; do
 	name=$(echo "${i}" | cut -d'|' -f2)
 
 	IMAGENAME="${BASENAME}-${name}"
+	IIDFILE=".${IMAGENAME}.iid"
+	IMAGETAG="${BASENAME}-${name}:${TAG}"
+	TARGET="${REGISTRY}/${IMAGETAG}"
 	echo "🔨 Assembling »${IMAGENAME}«"
-	ctr="$(buildah from "$basectr")"
-	buildah run "$ctr" /bin/sh -c 'apt-get update; \
-	DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
-	    build-essential \
-	    exim4-daemon-heavy \
-	    exim4-dev \
-	    gcovr \
-	    git \
-	    libsodium-dev \
-	    openssl \
-	    pkg-config \
-	    python3-pip \
-	    libxml2-utils; \
-	DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
-	    debhelper \
-	    debsigs \
-	    devscripts \
-	    dh-make \
-	    git-buildpackage \
-	    gpgv1 \
-	    meson; \
-	DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt-get install --no-install-recommends -y \
-	    vim; \
-	rm -rf /var/lib/apt/lists/*;'
-	buildah run "$ctr" /bin/sh -c \
-	    'pip3 install --upgrade meson ninja; \
-	    rm -rf ~/.cache/pip/*;'
-	TARGET="${REGISTRY}/${BASENAME}-${name}:${TAG}"
-	IMAGEID=$(buildah commit --format docker "$ctr" "${IMAGENAME}")
+	buildah build-using-dockerfile \
+		--from "${basectr}" \
+		--format docker \
+		--iidfile "${IIDFILE}" \
+		--tag "${IMAGETAG}"
+
 	if [ "${REGISTRY}" != "none" ]; then
-		echo "🚀 Pushing »${TARGET}«"
-		buildah push "${IMAGEID}" "${TARGET}"
+		echo "🚀 Pushing »${IMAGETAG}« to »${TARGET}«"
+		buildah push "${IMAGETAG}" "${TARGET}"
 		echo "✅ Finished »${BASENAME}«"
 	fi
+
+	rm -f "${IIDFILE}"
 done