diff --git a/wizard/pos_export_bc_wizard.py b/wizard/pos_export_bc_wizard.py
index 5aee81e..6ab743d 100644
--- a/wizard/pos_export_bc_wizard.py
+++ b/wizard/pos_export_bc_wizard.py
@@ -239,9 +239,9 @@ class PosExportBcWizard(models.TransientModel):
         end_str = self.end_date.strftime('%y%m%d')
         
         if export_all:
-            file_name = f"POS_{company_ident}_{start_str}_to_{end_str}_OLD_ALL.xls"
+            file_name = f"POS_{company_ident}_{start_str}_to_{end_str}_OLD_ALL.xlsx"
         elif old_format:
-            file_name = f"POS_{company_ident}_{start_str}_to_{end_str}_OLD.xls"
+            file_name = f"POS_{company_ident}_{start_str}_to_{end_str}_OLD.xlsx"
         else:
             file_name = f"POS_{company_ident}_{start_str}_to_{end_str}.xlsx"