diff --git a/src/BasicPathFinding.cs b/src/BasicPathFinding.cs
index 64d7688..f9064ec 100644
--- a/src/BasicPathFinding.cs
+++ b/src/BasicPathFinding.cs
@@ -173,7 +173,8 @@ namespace OpenSim.Modules.PathFinding
             {
                 for (int Y = (int)_start.Y; Y < (int)_end.Y; Y++)
                 {
-                    _map.SetPixel(X, Y, _color);
+                    if(Y >= 0 && Y >= 0)
+                        _map.SetPixel(X, Y, _color);
                 }
             }
         }