diff --git a/prop_mesher.cpp b/prop_mesher.cpp
index ae8729c..5fa37fc 100644
--- a/prop_mesher.cpp
+++ b/prop_mesher.cpp
@@ -548,22 +548,22 @@ void PropMesher::add_tiled_wall_simple(const int width, const int height, const
 
 void PropMesher::add_tiled_wall_mesh_rect_simple(const int x, const int y, const Transform &transform, const Rect2 &texture_rect) {
 	//x + 1, y
-	add_normal(transform.xform(Vector3(0, 0, 1)));
+	add_normal(transform.xform(Vector3(0, 0, -1)));
 	add_uv(transform_uv(Vector2(1, 1), texture_rect));
 	add_vertex(transform.xform(Vector3(x + 1, y, 0)));
 
 	//x, y
-	add_normal(transform.xform(Vector3(0, 0, 1)));
+	add_normal(transform.xform(Vector3(0, 0, -1)));
 	add_uv(transform_uv(Vector2(0, 1), texture_rect));
 	add_vertex(transform.xform(Vector3(x, y, 0)));
 
 	//x, y + 1
-	add_normal(transform.xform(Vector3(0, 0, 1)));
+	add_normal(transform.xform(Vector3(0, 0, -1)));
 	add_uv(transform_uv(Vector2(0, 0), texture_rect));
 	add_vertex(transform.xform(Vector3(x, y + 1, 0)));
 
 	//x + 1, y + 1
-	add_normal(transform.xform(Vector3(0, 0, 1)));
+	add_normal(transform.xform(Vector3(0, 0, -1)));
 	add_uv(transform_uv(Vector2(1, 0), texture_rect));
 	add_vertex(transform.xform(Vector3(x + 1, y + 1, 0)));