diff --git a/src/openttd.cpp b/src/openttd.cpp
index 3e11c9c3c7..223d514b4b 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -1416,8 +1416,8 @@ void CheckCaches(bool force_check, std::function<void(const char *)> log)
 		old_industry_stations_nears.push_back(ind->stations_near);
 	}
 
-	extern void RebuildTownCaches(bool cargo_update_required);
-	RebuildTownCaches(false);
+	extern void RebuildTownCaches(bool cargo_update_required, bool old_map_position);
+	RebuildTownCaches(false, false);
 	RebuildSubsidisedSourceAndDestinationCache();
 
 	Station::RecomputeCatchmentForAll();
diff --git a/src/saveload/town_sl.cpp b/src/saveload/town_sl.cpp
index 2811b9f7b4..7ec7f75f26 100644
--- a/src/saveload/town_sl.cpp
+++ b/src/saveload/town_sl.cpp
@@ -19,10 +19,19 @@
 
 #include "../safeguards.h"
 
+HouseID SLGetCleanHouseType(TileIndex t, bool old_map_position)
+{
+	if (old_map_position && SlXvIsFeatureMissing(XSLFI_MORE_HOUSES)) {
+		return _m[t].m4 | (GB(_m[t].m3, 6, 1) << 8);
+	} else {
+		return GetCleanHouseType(t);
+	}
+}
+
 /**
  * Rebuild all the cached variables of towns.
  */
-void RebuildTownCaches(bool cargo_update_required)
+void RebuildTownCaches(bool cargo_update_required, bool old_map_position)
 {
 	InitializeBuildingCounts();
 	RebuildTownKdtree();
@@ -36,7 +45,7 @@ void RebuildTownCaches(bool cargo_update_required)
 	for (TileIndex t = 0; t < MapSize(); t++) {
 		if (!IsTileType(t, MP_HOUSE)) continue;
 
-		HouseID house_id = GetHouseType(t);
+		HouseID house_id = GetTranslatedHouseID(SLGetCleanHouseType(t, old_map_position));
 		Town *town = Town::GetByTile(t);
 		IncreaseBuildingCount(town, house_id);
 		if (IsHouseCompleted(t)) town->cache.population += HouseSpec::Get(house_id)->population;
@@ -61,17 +70,13 @@ void RebuildTownCaches(bool cargo_update_required)
  */
 void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position)
 {
-	auto get_house_type = [&](TileIndex t) -> HouseID {
-		if (old_map_position && SlXvIsFeatureMissing(XSLFI_MORE_HOUSES)) {
-			return _m[t].m4 | (GB(_m[t].m3, 6, 1) << 8);
-		} else {
-			return GetCleanHouseType(t);
-		}
+	auto get_clean_house_type = [&](TileIndex t) -> HouseID {
+		return SLGetCleanHouseType(t, old_map_position);
 	};
 	for (TileIndex t = 0; t < MapSize(); t++) {
 		if (!IsTileType(t, MP_HOUSE)) continue;
 
-		HouseID house_id = get_house_type(t);
+		HouseID house_id = get_clean_house_type(t);
 		if (!HouseSpec::Get(house_id)->enabled && house_id >= NEW_HOUSE_OFFSET) {
 			/* The specs for this type of house are not available any more, so
 			 * replace it with the substitute original house type. */
@@ -90,24 +95,24 @@ void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position)
 	for (TileIndex t = 0; t < MapSize(); t++) {
 		if (!IsTileType(t, MP_HOUSE)) continue;
 
-		HouseID house_type = get_house_type(t);
+		HouseID house_type = get_clean_house_type(t);
 		TileIndex north_tile = t + GetHouseNorthPart(house_type); // modifies 'house_type'!
 		if (t == north_tile) {
 			const HouseSpec *hs = HouseSpec::Get(house_type);
 			bool valid_house = true;
 			if (hs->building_flags & TILE_SIZE_2x1) {
 				TileIndex tile = t + TileDiffXY(1, 0);
-				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_clean_house_type(tile) != house_type + 1) valid_house = false;
 			} else if (hs->building_flags & TILE_SIZE_1x2) {
 				TileIndex tile = t + TileDiffXY(0, 1);
-				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_clean_house_type(tile) != house_type + 1) valid_house = false;
 			} else if (hs->building_flags & TILE_SIZE_2x2) {
 				TileIndex tile = t + TileDiffXY(0, 1);
-				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 1) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_clean_house_type(tile) != house_type + 1) valid_house = false;
 				tile = t + TileDiffXY(1, 0);
-				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 2) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_clean_house_type(tile) != house_type + 2) valid_house = false;
 				tile = t + TileDiffXY(1, 1);
-				if (!IsTileType(tile, MP_HOUSE) || get_house_type(tile) != house_type + 3) valid_house = false;
+				if (!IsTileType(tile, MP_HOUSE) || get_clean_house_type(tile) != house_type + 3) valid_house = false;
 			}
 			/* If not all tiles of this house are present remove the house.
 			 * The other tiles will get removed later in this loop because
@@ -116,7 +121,7 @@ void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position)
 				DoClearSquare(t);
 				cargo_update_required = true;
 			}
-		} else if (!IsTileType(north_tile, MP_HOUSE) || get_house_type(north_tile) != house_type) {
+		} else if (!IsTileType(north_tile, MP_HOUSE) || get_clean_house_type(north_tile) != house_type) {
 			/* This tile should be part of a multi-tile building but the
 			 * north tile of this house isn't on the map. */
 			DoClearSquare(t);
@@ -124,7 +129,7 @@ void UpdateHousesAndTowns(bool cargo_update_required, bool old_map_position)
 		}
 	}
 
-	RebuildTownCaches(cargo_update_required);
+	RebuildTownCaches(cargo_update_required, old_map_position);
 }
 
 /** Save and load of towns. */