diff --git a/data/json/overmap/overmap_special/specials.json b/data/json/overmap/overmap_special/specials.json
index 912837b5475d..3e62f6fb69f3 100644
--- a/data/json/overmap/overmap_special/specials.json
+++ b/data/json/overmap/overmap_special/specials.json
@@ -2869,7 +2869,7 @@
     "city_sizes": [ 1, 16 ],
     "occurrences": [ 35, 100 ],
     "rotate": false,
-    "flags": [ "UNIQUE", "ELECTRIC_GRID" ]
+    "flags": [ "ELECTRIC_GRID", "UNIQUE", "GLOBALLY_UNIQUE" ]
   },
   {
     "type": "overmap_special",