diff --git a/core/src/com/unciv/logic/map/mapgenerator/MapGenerator.kt b/core/src/com/unciv/logic/map/mapgenerator/MapGenerator.kt
index 07120383ff..6c4a74bed9 100644
--- a/core/src/com/unciv/logic/map/mapgenerator/MapGenerator.kt
+++ b/core/src/com/unciv/logic/map/mapgenerator/MapGenerator.kt
@@ -102,12 +102,12 @@ class MapGenerator(val ruleset: Ruleset) {
     }
 
     private fun spreadAncientRuins(map: TileMap) {
-        if(map.mapParameters.noRuins)
+        if (map.mapParameters.noRuins || !ruleset.tileImprovements.containsKey(Constants.ancientRuins))
             return
         val suitableTiles = map.values.filter { it.isLand && !it.isImpassible() }
-        val locations = randomness.chooseSpreadOutLocations(suitableTiles.size/100,
+        val locations = randomness.chooseSpreadOutLocations(suitableTiles.size / 100,
                 suitableTiles, 10)
-        for(tile in locations)
+        for (tile in locations)
             tile.improvement = Constants.ancientRuins
     }