diff --git a/.vs/Obj2Tiles/DesignTimeBuild/.dtbcache.v2 b/.vs/Obj2Tiles/DesignTimeBuild/.dtbcache.v2
deleted file mode 100644
index 3b2a9dd..0000000
Binary files a/.vs/Obj2Tiles/DesignTimeBuild/.dtbcache.v2 and /dev/null differ
diff --git a/Obj2Tiles/Options.cs b/Obj2Tiles/Options.cs
index afa4c9e..926a274 100644
--- a/Obj2Tiles/Options.cs
+++ b/Obj2Tiles/Options.cs
@@ -47,8 +47,8 @@ public sealed class Options
     [Option("keep-intermediate", Required = false, HelpText = "Keeps the intermediate files (do not cleanup)", Default = false)]
     public bool KeepIntermediateFiles { get; set; }
 
-    [Option('t',"yuptozup", Required = false, HelpText = "Convert the upward Y-axis to the upward Z-axis, which is used in some situations where the upward axis may be the Y-axis or the Z-axis after the obj is exported.", Default = true)]
-    public bool YUpToZUp { get; set; }
+    [Option('t', "y-up-to-z-up", Required = true, HelpText = "Convert the upward Y-axis to the upward Z-axis, which is used in some situations where the upward axis may be the Y-axis or the Z-axis after the obj is exported.", Default = true)]
+    public bool? YUpToZUp { get; set; }
 }
 
 public enum Stage
diff --git a/Obj2Tiles/Program.cs b/Obj2Tiles/Program.cs
index 9ee33f1..2834a25 100644
--- a/Obj2Tiles/Program.cs
+++ b/Obj2Tiles/Program.cs
@@ -82,7 +82,7 @@ private static async Task Run(Options opts)
                     return;
 
                 var gpsCoords = opts.Latitude != null && opts.Longitude != null
-                    ? new GpsCoords(opts.Latitude.Value, opts.Longitude.Value, opts.Altitude, opts.Scale, opts.YUpToZUp)
+                    ? new GpsCoords(opts.Latitude.Value, opts.Longitude.Value, opts.Altitude, opts.Scale, opts.YUpToZUp == true)
                     : null;
 
                 Console.WriteLine();