diff --git a/commission.py b/commission.py
index 80a6a16..72218ef 100644
--- a/commission.py
+++ b/commission.py
@@ -3,24 +3,35 @@
 # the full copyright notices and license terms.
 from trytond.pool import Pool, PoolMeta
 from trytond.tools import grouped_slice
+from trytond.transaction import Transaction
+from sql.operators import Concat
 
 
 class Invoice(metaclass=PoolMeta):
     __name__ = 'account.invoice'
 
-    def get_allow_draft(self, name):
+    @classmethod
+    def get_allow_draft(cls, invoices, name):
         pool = Pool()
         Commission = pool.get('commission')
+        Line = pool.get('account.invoice.line')
+
+        res = super().get_allow_draft(invoices, name)
+
+        line = Line.__table__()
+        commission = Commission.__table__()
+
+        invoice_ids = [i.id for i in invoices]
+        query = line.join(commission,
+            condition=commission.origin == Concat('account.invoice.line,', line.id)
+            ).select(line.invoice, where=line.invoice.in_(invoice_ids))
 
-        result = super().get_allow_draft(name)
+        cursor = Transaction().connection.cursor()
+        cursor.execute(*query)
+        for record in cursor.fetchall():
+            res[record[0]] = False
 
-        invoiced = Commission.search([
-                ('origin.invoice', '=', self.id, 'account.invoice.line'),
-                ('invoice_line', '!=', None),
-                ])
-        if invoiced:
-            result = False
-        return result
+        return res
 
     @classmethod
     def draft(cls, invoices):
diff --git a/invoice.py b/invoice.py
index 321917d..d8b5764 100644
--- a/invoice.py
+++ b/invoice.py
@@ -9,7 +9,6 @@
 
 class Invoice(metaclass=PoolMeta):
     __name__ = 'account.invoice'
-
     allow_draft = fields.Function(
         fields.Boolean("Allow Draft Invoice"), 'get_allow_draft')
 
@@ -20,25 +19,31 @@ def __setup__(cls):
         cls._buttons['draft']['invisible'] = ~Eval('allow_draft', False)
         cls._buttons['draft']['depends'] += tuple(['allow_draft'])
 
-    def get_allow_draft(self, name):
-        # when IN invoice is validate from scratch, the move is in 'draft'
-        # state, so in this case could be draft in a "normal" way
-        if (self.state == 'validated' and self.move
-                and self.move.state != 'draft'):
-            return False
-        elif self.state == 'cancelled' and self.number is not None:
-            return False
-        elif self.state in {'paid', 'draft'}:
-            return False
-        elif self.state == 'posted':
-            lines_to_pay = [l for l in self.lines_to_pay
-                if not l.reconciliation]
-            # Invoice already paid or partial paid, should not be possible
-            # to change state to draft.
-            if (not lines_to_pay
-                    or self.amount_to_pay != self.total_amount):
-                return False
-        return True
+    @classmethod
+    def get_allow_draft(cls, invoices, name):
+        res = dict((x.id, False) for x in invoices)
+
+        for invoice in invoices:
+            # when IN invoice is validate from scratch, the move is in 'draft'
+            # state, so in this case could be draft in a "normal" way
+            if (invoice.state == 'validated' and invoice.move
+                    and invoice.move.state != 'draft'):
+                continue
+            elif invoice.state == 'cancelled' and invoice.number is not None:
+                continue
+            elif invoice.state in {'paid', 'draft'}:
+                continue
+            elif invoice.state == 'posted':
+                lines_to_pay = [l for l in invoice.lines_to_pay
+                    if not l.reconciliation]
+                # Invoice already paid or partial paid, should not be possible
+                # to change state to draft.
+                if (not lines_to_pay
+                        or invoice.amount_to_pay != invoice.total_amount):
+                    continue
+            # in case not continue, set to True
+            res[invoice.id] = True
+        return res
 
     @classmethod
     def draft(cls, invoices):