diff --git a/Shoko.Server/API/v3/Models/Shoko/ScrobblingFileResult.cs b/Shoko.Server/API/v3/Models/Shoko/ScrobblingFileResult.cs
index 8a7de915a..5574dcebb 100644
--- a/Shoko.Server/API/v3/Models/Shoko/ScrobblingFileResult.cs
+++ b/Shoko.Server/API/v3/Models/Shoko/ScrobblingFileResult.cs
@@ -1,5 +1,8 @@
+using System;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Net.Http.Headers;
 using Shoko.Server.Models;
@@ -27,9 +30,54 @@ public ScrobblingFileResult(SVR_VideoLocal videoLocal, int userID, string fileNa
     public override async Task ExecuteResultAsync(ActionContext context)
     {
         await base.ExecuteResultAsync(context);
+        var (_, end) = GetRange(context.HttpContext, VideoLocal.FileSize);
+        if (end != VideoLocal.FileSize) return;
 #pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
         Task.Factory.StartNew(() => VideoLocal.ToggleWatchedStatus(true, UserID), new CancellationToken(), TaskCreationOptions.LongRunning,
-#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
             TaskScheduler.Default);
+#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
+    }
+
+    private static (long start, long end) GetRange(HttpContext context, long length)
+    {
+        if (length == 0) return (0, 0);
+        var requestHeaders = context.Request.GetTypedHeaders();
+        var rangeHeader = requestHeaders.Range;
+        if (rangeHeader == null) return (0, length);
+        var ranges = rangeHeader.Ranges;
+        if (ranges.Count == 0) return (0, length);
+
+        var range = ranges.First();
+        var start = range.From;
+        var end = range.To;
+
+        // X-[Y]
+        if (start.HasValue)
+        {
+            if (start.Value >= length)
+            {
+                // Not satisfiable, skip/discard.
+                return (0, length);
+            }
+            if (!end.HasValue || end.Value >= length)
+            {
+                end = length - 1;
+            }
+        }
+        else if (end.HasValue)
+        {
+            // suffix range "-X" e.g. the last X bytes, resolve
+            if (end.Value == 0)
+            {
+                // Not satisfiable, skip/discard.
+                return (0, length);
+            }
+
+            var bytes = Math.Min(end.Value, length);
+            start = length - bytes;
+            end = start + bytes - 1;
+        }
+
+        return (start ?? 0, end ?? length);
     }
 }