diff --git a/src/bnhtrade.Core/Logic/Export/AmazonSettlement.cs b/src/bnhtrade.Core/Logic/Export/AmazonSettlement.cs
index 3fbae60..5826447 100644
--- a/src/bnhtrade.Core/Logic/Export/AmazonSettlement.cs
+++ b/src/bnhtrade.Core/Logic/Export/AmazonSettlement.cs
@@ -222,7 +222,10 @@ namespace bnhtrade.Core.Logic.Export
                         if (invoiceList[i].InvoiceLineList.Count == 0)
                         {
                             invoiceList.RemoveAt(i);
-                            i = i - 1;
+                            if (i > 0)
+                            {
+                                i = i - 1;
+                            }
                         }
                     }
                     // get here add info to lines