diff --git a/biomes/.util/ruined_portals.json b/biomes/.util/ruined_portals.json
index 9a0bce4c..bb8bc798 100644
--- a/biomes/.util/ruined_portals.json
+++ b/biomes/.util/ruined_portals.json
@@ -59,6 +59,7 @@
         {
             "name": "standard-underground",
             "chance": 0.2,
+            "mode": "VACUUM",
             "place": [
                 "clutter/swordnp2",
                 "clutter/swordnp1",