diff --git a/docker/backend/Dockerfile b/docker/backend/Dockerfile
index 2b89763f6..8be8d43f0 100644
--- a/docker/backend/Dockerfile
+++ b/docker/backend/Dockerfile
@@ -46,8 +46,8 @@ RUN stack install yesod-bin
 RUN stack install hpack
 
 # pre-build dependencies
-RUN make -- --dependencies-backend STACK_ROOT=${STACK_ROOT} IN_CONTAINER=true JOB=${JOB}
-COPY . ${PROJECT_DIR}
+RUN --mount=type=bind,source=.,target=${PROJECT_DIR} \
+make -- --dependencies-backend STACK_ROOT=${STACK_ROOT} IN_CONTAINER=true JOB=${JOB}
 
 # copy source files
 #COPY app/ ${PROJECT_DIR}/app