diff --git a/docker/backend/Dockerfile b/docker/backend/Dockerfile
index bc2ee5299..088d60bd2 100644
--- a/docker/backend/Dockerfile
+++ b/docker/backend/Dockerfile
@@ -10,19 +10,20 @@ ENV LANG=en_US.UTF-8
 # in CI-pipelines these two should be different, so that the container caches the compilation results.
 ARG MOUNT_DIR=/mnt/fradrive
 ARG PROJECT_DIR=/fradrive
-RUN mkdir -p ${PROJECT_DIR}
-RUN if [ "${PROJECT_DIR}" != "${MOUNT_DIR}" ] ; then cp -r ${MOUNT_DIR}/* ${PROJECT_DIR} ; fi
-WORKDIR ${PROJECT_DIR}
-ENV HOME=${PROJECT_DIR}
 
-RUN mkdir -p /.stack
-ENV STACK_ROOT=/.stack
+RUN mkdir -p "${PROJECT_DIR}"
+RUN if [ "${PROJECT_DIR}" != "${MOUNT_DIR}" ] ; then cp -r "${MOUNT_DIR}"/* "${PROJECT_DIR}" ; fi
+WORKDIR "${PROJECT_DIR}"
+ENV HOME="${PROJECT_DIR}"
+
+RUN mkdir -p "${PROJECT_DIR}/.stack"
+ENV STACK_ROOT="${PROJECT_DIR}/.stack"
 
 RUN make .stack STACK_ROOT=${STACK_ROOT} IN_CONTAINER=true
 RUN stack build yesod-bin
 
 ENV FRADRIVE_MAKE_TARGET=serve-backend
-ENTRYPOINT make -- ${FRADRIVE_MAKE_TARGET} STACK_ROOT=${STACK_ROOT} IN_CONTAINER=true
+ENTRYPOINT make -- ${FRADRIVE_MAKE_TARGET} STACK_ROOT="${STACK_ROOT}" IN_CONTAINER=true
 
 EXPOSE 3000/tcp
 EXPOSE 3443/tcp
\ No newline at end of file