diff --git a/docker/backend/Dockerfile b/docker/backend/Dockerfile
index 8be8d43f0..36e8b11ac 100644
--- a/docker/backend/Dockerfile
+++ b/docker/backend/Dockerfile
@@ -46,7 +46,7 @@ RUN stack install yesod-bin
 RUN stack install hpack
 
 # pre-build dependencies
-RUN --mount=type=bind,source=.,target=${PROJECT_DIR} \
+RUN --mount=type=bind,source=.,target=. \
 make -- --dependencies-backend STACK_ROOT=${STACK_ROOT} IN_CONTAINER=true JOB=${JOB}
 
 # copy source files