diff --git a/aeat.py b/aeat.py
index 667cd77..8df5007 100644
--- a/aeat.py
+++ b/aeat.py
@@ -851,8 +851,8 @@ class SIIReportLine(ModelSQL, ModelView):
     __name__ = 'aeat.sii.report.lines'
 
     report = fields.Many2One(
-        'aeat.sii.report', 'Issued Report', ondelete='CASCADE')
-    invoice = fields.Many2One('account.invoice', 'Invoice',
+        'aeat.sii.report', 'Issued Report', ondelete='CASCADE', select=True)
+    invoice = fields.Many2One('account.invoice', 'Invoice', select=True,
         states={
             'required': Eval('_parent_report', {}).get(
                 'operation_type') != 'C0',
@@ -937,7 +937,7 @@ class SIIReportLineTax(ModelSQL, ModelView):
     __name__ = 'aeat.sii.report.line.tax'
 
     line = fields.Many2One(
-        'aeat.sii.report.lines', 'Report Line', ondelete='CASCADE')
+        'aeat.sii.report.lines', 'Report Line', ondelete='CASCADE', select=True)
 
     base = fields.Numeric('Base', readonly=True)
     rate = fields.Numeric('Rate', readonly=True)