diff --git a/Source/Core/Map/Sector.cs b/Source/Core/Map/Sector.cs
index 6341c010102cbd52eb2d0f5979e2cb075312573e..cd0957e43bb4af125d29f2eaf5386edca9deaea4 100644
--- a/Source/Core/Map/Sector.cs
+++ b/Source/Core/Map/Sector.cs
@@ -520,7 +520,8 @@ namespace CodeImp.DoomBuilder.Map
 		// This checks if the given point is inside the sector polygon
 		public bool Intersect(Vector2D p) 
 		{
-			if(!bbox.Contains(p.x, p.y)) return false; //mxd. Check bounding box first
+			//mxd. Check bounding box first
+			if(p.x < bbox.Left || p.x > bbox.Right || p.y < bbox.Top || p.y > bbox.Bottom) return false;
 			
 			uint c = 0;