diff --git a/PKHeX.Core/Editing/Saves/BoxManip/BoxManipParam.cs b/PKHeX.Core/Editing/Saves/BoxManip/BoxManipParam.cs
index 8f58f8136..7af44c6c5 100644
--- a/PKHeX.Core/Editing/Saves/BoxManip/BoxManipParam.cs
+++ b/PKHeX.Core/Editing/Saves/BoxManip/BoxManipParam.cs
@@ -1,9 +1,9 @@
-namespace PKHeX.Core;
+namespace PKHeX.Core;
 
 /// <summary>
 /// Criteria for manipulating box data.
 /// </summary>
 /// <param name="Start">Box to start at (inclusive)</param>
-/// <param name="Stop">Box to stop at (exclusive)</param>
+/// <param name="Stop">Box to stop after (inclusive)</param>
 /// <param name="Reverse">Iterate in reverse</param>
 public readonly record struct BoxManipParam(int Start, int Stop, bool Reverse = false);
diff --git a/PKHeX.Core/Saves/SaveFile.cs b/PKHeX.Core/Saves/SaveFile.cs
index 9ff0962d1..f86e77530 100644
--- a/PKHeX.Core/Saves/SaveFile.cs
+++ b/PKHeX.Core/Saves/SaveFile.cs
@@ -741,7 +741,7 @@ public int ClearBoxes(int BoxStart = 0, int BoxEnd = -1, Func<PKM, bool>? delete
     {
         var storage = BoxBuffer.AsSpan();
 
-        if (BoxEnd < 0)
+        if ((uint)BoxEnd >= BoxCount)
             BoxEnd = BoxCount - 1;
 
         var blank = GetDataForBox(BlankPKM);
@@ -778,7 +778,7 @@ public int ClearBoxes(int BoxStart = 0, int BoxEnd = -1, Func<PKM, bool>? delete
     /// <returns>Count of modified <see cref="PKM"/> slots.</returns>
     public int ModifyBoxes(Action<PKM> action, int BoxStart = 0, int BoxEnd = -1)
     {
-        if (BoxEnd < 0)
+        if ((uint)BoxEnd >= BoxCount)
             BoxEnd = BoxCount - 1;
 
         var storage = BoxBuffer.AsSpan();
diff --git a/PKHeX.WinForms/Subforms/SAV_Database.cs b/PKHeX.WinForms/Subforms/SAV_Database.cs
index b43955fba..25f906391 100644
--- a/PKHeX.WinForms/Subforms/SAV_Database.cs
+++ b/PKHeX.WinForms/Subforms/SAV_Database.cs
@@ -681,7 +681,7 @@ private void Menu_DeleteClones_Click(object sender, EventArgs e)
         }
 
         var boxClear = new BoxManipClearDuplicate<string>(BoxManipType.DeleteClones, pk => SearchUtil.GetCloneDetectMethod(method)(pk));
-        var param = new BoxManipParam(0, SAV.BoxCount);
+        var param = new BoxManipParam(0, SAV.BoxCount - 1);
         int count = boxClear.Execute(SAV, param);
         deleted += count;