diff --git a/CodeWalker.Core/GameFiles/FileTypes/YmapFile.cs b/CodeWalker.Core/GameFiles/FileTypes/YmapFile.cs
index a1f7cd9..09a5e5a 100644
--- a/CodeWalker.Core/GameFiles/FileTypes/YmapFile.cs
+++ b/CodeWalker.Core/GameFiles/FileTypes/YmapFile.cs
@@ -3309,6 +3309,7 @@ namespace CodeWalker.GameFiles
             Vertices = MetaTypes.ConvertDataArray<Vector3>(Data, 0, vertexCount);
             Indices = new byte[indexCount];
             Buffer.BlockCopy(Data, indicesOffset, Indices, 0, indexCount);
+            BuildTriangles();
         }