diff --git a/PKHeX.WinForms/Util/WinFormsUtil.cs b/PKHeX.WinForms/Util/WinFormsUtil.cs
index 72e5818e7..2dd5acbc6 100644
--- a/PKHeX.WinForms/Util/WinFormsUtil.cs
+++ b/PKHeX.WinForms/Util/WinFormsUtil.cs
@@ -162,6 +162,8 @@ internal static int getIndex(ComboBox cb)
         public static void PanelScroll(object sender, ScrollEventArgs e)
         {
             var p = sender as Panel;
+            if (e.NewValue < 0)
+                return;
             switch (e.ScrollOrientation)
             {
                 case ScrollOrientation.HorizontalScroll: