diff --git a/automated/build.sh b/automated/build.sh
index 3d92d45d..08a344a8 100755
--- a/automated/build.sh
+++ b/automated/build.sh
@@ -68,6 +68,6 @@ ARGS_BUILD="$ARGS_COMMON -v $CABAL_DIR:/home/stackage/.cabal:ro -v $GHC_DIR:/hom
 ARGS_UPLOAD="$ARGS_COMMON -v $AUTH_TOKEN:/auth-token:ro -v $HACKAGE_CREDS:/hackage-creds:ro -v $CURATOR_DIR:/home/stackage/.stackage-curator -v $SSH_DIR:/home/ubuntu/.ssh:ro -v $GITCONFIG:/home/stackage/.gitconfig:ro"
 
 # Use cabal update first to initialize ~/.cabal.config, then use stackage-curator update to get it securely
-docker run $ARGS_PREBUILD snoyberg/stackage /bin/bash -c "cabal update && stackage-curator update && stackage-curator create-plan --plan-file $PLAN_FILE --target $TARGET && stackage-curator check --plan-file $PLAN_FILE && stackage-curator fetch --plan-file $PLAN_FILE && cabal install random cabal-install"
+docker run $ARGS_PREBUILD snoyberg/stackage /bin/bash -c "cabal update && stackage-curator update && stackage-curator create-plan --plan-file $PLAN_FILE --target $TARGET ${CONSTRAINTS:-} && stackage-curator check --plan-file $PLAN_FILE && stackage-curator fetch --plan-file $PLAN_FILE && cabal install random cabal-install"
 docker run $ARGS_BUILD snoyberg/stackage stackage-curator make-bundle --plan-file $PLAN_FILE --bundle-file $BUNDLE_FILE --target $TARGET
 docker run $ARGS_UPLOAD snoyberg/stackage /bin/bash -c "stackage-curator upload --bundle-file $BUNDLE_FILE && stackage-curator hackage-distro --plan-file $PLAN_FILE --target $TARGET && stackage-curator upload-github --plan-file $PLAN_FILE --target $TARGET"