diff --git a/Dockerfile-build-arch b/Dockerfile-build-arch
index 55a5e7eb..e7dad982 100644
--- a/Dockerfile-build-arch
+++ b/Dockerfile-build-arch
@@ -16,14 +16,17 @@ ARG BUILD_PACKAGES="\
 	wt \
 	xxhash"
 
-RUN	pacman -Syu --noconfirm
-RUN pacman -S --noconfirm ${BUILD_PACKAGES}
+RUN pacman -Syu --noconfirm ${BUILD_PACKAGES} && \
+	pacman -Scc --noconfirm && \
+	rm -rf /var/cache/pacman/pkg/*
 
 # LMS
 COPY . /tmp/lms/
-ARG LMS_BUILD_TYPE="Release"
-RUN \
-	DIR=/tmp/lms/build && mkdir -p ${DIR} && cd ${DIR}  && \
-		cmake /tmp/lms/ -DCMAKE_BUILD_TYPE=${LMS_BUILD_TYPE} -DCMAKE_INSTALL_PREFIX=/usr -DLMS_IMAGE_BACKEND=graphicsmagick -DBUILD_BENCHMARKS=ON && \
-		VERBOSE=1 make -j$(nproc) && \
-		make test
+RUN mkdir -p /tmp/lms/build
+WORKDIR /tmp/lms/build
+
+ARG LMS_BUILD_TYPE=Release
+ARG LMS_UNITY_BUILD=ON
+RUN cmake .. -DCMAKE_BUILD_TYPE=${LMS_BUILD_TYPE} -DCMAKE_UNITY_BUILD=${LMS_UNITY_BUILD} -DLMS_IMAGE_BACKEND=graphicsmagick -DBUILD_BENCHMARKS=ON
+RUN VERBOSE=1 make -j$(nproc)
+RUN make test