diff --git a/Program.cs b/Program.cs
index bfa3a85..f7d8c65 100644
--- a/Program.cs
+++ b/Program.cs
@@ -395,7 +395,7 @@ public static class Util {
     var operations = new Dictionary<ushort, (RotateMode, FlipMode)> {
       { 2, (RotateMode.None, FlipMode.Horizontal) },
       { 3, (RotateMode.Rotate180, FlipMode.None) },
-      { 4, (RotateMode.Rotate180, FlipMode.Horizontal) },
+      { 4, (RotateMode.None, FlipMode.Vertical) },
       { 5, (RotateMode.Rotate90, FlipMode.Vertical) },
       { 6, (RotateMode.Rotate90, FlipMode.None) },
       { 7, (RotateMode.Rotate270, FlipMode.Vertical) },