diff --git a/src/field_specials.c b/src/field_specials.c
index 6aa62d22f4..2e33b443ca 100644
--- a/src/field_specials.c
+++ b/src/field_specials.c
@@ -868,7 +868,7 @@ static void PetalburgGymSetDoorMetatiles(u8 roomNumber, u16 metatileId)
     for (i = 0; i < nDoors; i++)
     {
         MapGridSetMetatileIdAt(doorCoordsX[i] + MAP_OFFSET, doorCoordsY[i] + MAP_OFFSET, metatileId | MAPGRID_COLLISION_MASK);
-        MapGridSetMetatileIdAt(doorCoordsX[i] + MAP_OFFSET, doorCoordsY[i] + MAP_OFFSET + 1, (metatileId + 8) | MAPGRID_COLLISION_MASK);
+        MapGridSetMetatileIdAt(doorCoordsX[i] + MAP_OFFSET, doorCoordsY[i] + MAP_OFFSET + 1, (metatileId + METATILE_ROW_WIDTH) | MAPGRID_COLLISION_MASK);
     }
     DrawWholeMapView();
 }