diff --git a/MP4/box_trak.h b/MP4/box_trak.h
index 31f93a88..a986925c 100644
--- a/MP4/box_trak.h
+++ b/MP4/box_trak.h
@@ -8,10 +8,10 @@ class Box_trak {
     ~Box_trak();
     Box * GetBox();
     void AddContent( Box * newcontent, uint32_t offset = 0 );
+    void WriteContent( );
   private:
     Box * Container;
 
-    void WriteContent( );
     std::vector<Box *> Content;
 };//Box_ftyp Class