diff --git a/demo/bin/multilevel_astar.gd b/demo/bin/multilevel_astar.gd
index 7d43c53..3abcdb6 100644
--- a/demo/bin/multilevel_astar.gd
+++ b/demo/bin/multilevel_astar.gd
@@ -16,7 +16,7 @@ func _init(map: TileMap):
 	_used_rect = map.get_used_rect()
 	
 	# assert stuff here because the extension's assertions just crash without a message
-	assert(_used_rect.get_area() > 0)
+	assert(_used_rect.get_area() >= 0)
 	
 	_astar = MultilevelAStarEx.new()
 	_astar.init(_used_rect)
diff --git a/src/MultilevelAStarEx.cpp b/src/MultilevelAStarEx.cpp
index 32ba880..3d682cd 100644
--- a/src/MultilevelAStarEx.cpp
+++ b/src/MultilevelAStarEx.cpp
@@ -79,7 +79,7 @@ void MultilevelAStarEx::init(const Rect2i &region)
 {
 	DEV_ASSERT(!_init);
 
-	DEV_ASSERT(region.get_area() > 0);
+	DEV_ASSERT(region.get_area() >= 0);
 
 	_region = region;
 	_width = region.get_size().width;