diff --git a/deploy/deploy.sh b/deploy/deploy.sh
index b0c135e..e367b4e 100755
--- a/deploy/deploy.sh
+++ b/deploy/deploy.sh
@@ -39,7 +39,9 @@ cp deploy/compose.yaml "$STACK/compose.yaml"
 set_setting GK_TAG "$TAG"
 [ -n "$CURRENT" ] && set_setting GK_PREVIOUS_TAG "$CURRENT"
 
-if ! compose up -d --remove-orphans --wait --wait-timeout 120; then
+# No --remove-orphans: another stack may share the project name, and its
+# containers must never be touched by this deploy.
+if ! compose up -d --wait --wait-timeout 120; then
   echo "!! $TAG did not come up healthy"
   compose ps
   compose logs --tail 50 || true