diff --git a/src/newgrf_commons.cpp b/src/newgrf_commons.cpp
index 5d6aa6630b..6ffd879e0d 100644
--- a/src/newgrf_commons.cpp
+++ b/src/newgrf_commons.cpp
@@ -252,7 +252,7 @@ uint32 GetTerrainType(TileIndex tile)
 {
 	switch (_opt.landscape) {
 		case LT_TROPIC: return GetTropicZone(tile) == TROPICZONE_DESERT ? 1 : 2;
-		case LT_ARCTIC: return GetTileZ(tile) >= GetSnowLine() ? 4 : 0;
+		case LT_ARCTIC: return GetTileZ(tile) > GetSnowLine() ? 4 : 0;
 		default:        return 0;
 	}
 }