diff --git a/FFMpegCore/FFMpeg/Builders/MetaData/ChapterData.cs b/FFMpegCore/FFMpeg/Builders/MetaData/ChapterData.cs
index d0b5bcb..e278408 100644
--- a/FFMpegCore/FFMpeg/Builders/MetaData/ChapterData.cs
+++ b/FFMpegCore/FFMpeg/Builders/MetaData/ChapterData.cs
@@ -6,15 +6,13 @@ public class ChapterData
         public TimeSpan Start { get; private set; }
         public TimeSpan End { get; private set; }
 
-        public TimeSpan Duration { get; private set; }
+        public TimeSpan Duration => End - Start;
 
         public ChapterData(string title, TimeSpan start, TimeSpan end)
         {
             Title = title;
             Start = start;
             End = end;
-
-            Duration = end - start;
         }
     }
 }