diff --git a/src/DotRecast.Detour/Io/NavMeshTileHeader.cs b/src/DotRecast.Detour/Io/NavMeshTileHeader.cs
index 3502fcb..c2f938a 100644
--- a/src/DotRecast.Detour/Io/NavMeshTileHeader.cs
+++ b/src/DotRecast.Detour/Io/NavMeshTileHeader.cs
@@ -1,6 +1,6 @@
 namespace DotRecast.Detour.Io
 {
-    public class NavMeshTileHeader
+    public struct NavMeshTileHeader
     {
         public long tileRef;
         public int dataSize;