diff --git a/odoo/addons/base/models/ir_sequence.py b/odoo/addons/base/models/ir_sequence.py
index a356ddfaa47..3e13dccdade 100644
--- a/odoo/addons/base/models/ir_sequence.py
+++ b/odoo/addons/base/models/ir_sequence.py
@@ -3,7 +3,7 @@
 from datetime import datetime, timedelta
 import logging
 import pytz
-from psycopg2 import sql
+from psycopg2 import sql, OperationalError, errorcodes
 
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError
@@ -53,8 +53,14 @@ def _select_nextval(cr, seq_name):
 
 def _update_nogap(self, number_increment):
     number_next = self.number_next
-    self._cr.execute("SELECT number_next FROM %s WHERE id=%%s FOR UPDATE NOWAIT" % self._table, [self.id])
-    self._cr.execute("UPDATE %s SET number_next=number_next+%%s WHERE id=%%s " % self._table, (number_increment, self.id))
+    try:
+        self._cr.execute("SELECT number_next FROM %s WHERE id=%%s FOR UPDATE NOWAIT" % self._table, [self.id])
+        self._cr.execute("UPDATE %s SET number_next=number_next+%%s WHERE id=%%s " % self._table, (number_increment, self.id))
+    except OperationalError as e:
+        if e.pgcode == errorcodes.LOCK_NOT_AVAILABLE:
+            raise UserError(_("This transaction wasn't executed because another transaction is already using the same no-gap sequence. Please try again later."))
+        else:
+            raise
     self.invalidate_cache(['number_next'], [self.id])
     return number_next
 
diff --git a/odoo/addons/base/tests/test_ir_sequence.py b/odoo/addons/base/tests/test_ir_sequence.py
index 0fc53012b48..8c27dc18d74 100644
--- a/odoo/addons/base/tests/test_ir_sequence.py
+++ b/odoo/addons/base/tests/test_ir_sequence.py
@@ -7,6 +7,7 @@ import psycopg2
 import psycopg2.errorcodes
 
 import odoo
+from odoo.exceptions import UserError
 from odoo.tests import common
 from odoo.tests.common import BaseCase
 
@@ -92,11 +93,10 @@ class TestIrSequenceNoGap(BaseCase):
         with environment() as env0:
             with environment() as env1:
                 env1.cr._default_log_exceptions = False # Prevent logging a traceback
-                with self.assertRaises(psycopg2.OperationalError) as e:
+                with self.assertRaises(UserError) as e:
                     n0 = env0['ir.sequence'].next_by_code('test_sequence_type_2')
                     self.assertTrue(n0)
                     n1 = env1['ir.sequence'].next_by_code('test_sequence_type_2')
-                self.assertEqual(e.exception.pgcode, psycopg2.errorcodes.LOCK_NOT_AVAILABLE, msg="postgresql returned an incorrect errcode")
 
     @classmethod
     def tearDownClass(cls):