diff --git a/purchase.py b/purchase.py
index 9919d0994d..2db4ef093d 100644
--- a/purchase.py
+++ b/purchase.py
@@ -6,7 +6,7 @@ from itertools import chain
 from trytond import backend
 from trytond.i18n import gettext
 from trytond.pool import PoolMeta, Pool
-from trytond.pyson import Eval, Bool, If
+from trytond.pyson import Eval, Bool, If, Id
 from trytond.model import Workflow, ModelView, fields, ModelSQL, \
         sequence_ordered
 from trytond.model.exceptions import RequiredValidationError, AccessError
@@ -26,7 +26,9 @@ class Configuration(metaclass=PoolMeta):
             domain=[
                 ('company', 'in',
                     [Eval('context', {}).get('company', -1), None]),
-                ('code', '=', 'purchase.requisition'),
+                ('sequence_type', '=',
+                    Id('purchase_requisition',
+                        'sequence_type_purchase_requisition')),
                 ]))
 
     @classmethod
@@ -48,7 +50,9 @@ class ConfigurationSequence(metaclass=PoolMeta):
         'ir.sequence', "Purchase Requisition Sequence", required=True,
         domain=[
             ('company', 'in', [Eval('company', -1), None]),
-            ('code', '=', 'purchase.requisition'),
+            ('sequence_type', '=',
+                Id('purchase_requisition',
+                    'sequence_type_purchase_requisition')),
             ],
         depends=['company'])
 
@@ -319,15 +323,14 @@ class PurchaseRequisition(Workflow, ModelSQL, ModelView):
     @classmethod
     def create(cls, vlist):
         pool = Pool()
-        Sequence = pool.get('ir.sequence')
         Config = pool.get('purchase.configuration')
 
         config = Config(1)
         vlist = [v.copy() for v in vlist]
         for values in vlist:
             if values.get('number') is None:
-                values['number'] = Sequence.get_id(
-                    config.purchase_requisition_sequence.id)
+                values['number'] = (
+                    config.purchase_requisition_sequence.get())
         return super(PurchaseRequisition, cls).create(vlist)
 
     @classmethod
diff --git a/purchase.xml b/purchase.xml
index 5431efc4ef..4d4dca475a 100644
--- a/purchase.xml
+++ b/purchase.xml
@@ -159,7 +159,6 @@ this repository contains the full copyright notices and license terms.
         <record model="ir.sequence.type"
             id="sequence_type_purchase_requisition">
             <field name="name">Purchase Requisition</field>
-            <field name="code">purchase.requisition</field>
         </record>
         <record model="ir.sequence.type-res.group"
             id="sequence_type_purchase_requisition_group_admin">
@@ -175,7 +174,7 @@ this repository contains the full copyright notices and license terms.
         </record>
         <record model="ir.sequence" id="sequence_purchase_requisition">
             <field name="name">Purchase Requisition</field>
-            <field name="code">purchase.requisition</field>
+            <field name="sequence_type" ref="sequence_type_purchase_requisition"/>
         </record>
 
         <record model="ir.model.button" id="requisition_cancel_button">