diff --git a/runbot/models/repo.py b/runbot/models/repo.py
index f13c5a09..af448227 100644
--- a/runbot/models/repo.py
+++ b/runbot/models/repo.py
@@ -270,10 +270,9 @@ class runbot_repo(models.Model):
         max_age = int(icp.get_param('runbot.runbot_max_age', default=30))
 
         self.env.cr.execute("""
-            WITH t (build, branch_id) AS (SELECT unnest(%s), unnest(%s))
-          SELECT b.name, b.branch_id
-            FROM t LEFT JOIN runbot_build b ON (b.name = t.build) AND (b.branch_id = t.branch_id)
-        """, ([r[1] for r in refs], [ref_branches[r[0]] for r in refs]))
+            SELECT DISTINCT ON (branch_id) name, branch_id
+            FROM runbot_build WHERE branch_id in %s ORDER BY branch_id,id DESC;
+        """, (tuple([ref_branches[r[0]] for r in refs]),))
         # generate a set of tuples (branch_id, sha)
         builds_candidates = {(r[1], r[0]) for r in self.env.cr.fetchall()}
 
diff --git a/runbot/tests/test_repo.py b/runbot/tests/test_repo.py
index 54e831b9..91d44276 100644
--- a/runbot/tests/test_repo.py
+++ b/runbot/tests/test_repo.py
@@ -57,7 +57,7 @@ class Test_Repo(common.TransactionCase):
             'name': 'refs/heads/bidon'
         })
 
-        self.commit_list = [('refs/heads/bidon',
+        first_commit = [('refs/heads/bidon',
                              'd0d0caca',
                              datetime.datetime.now().strftime("%Y-%m-%d, %H:%M:%S"),
                              'Marc Bidule',
@@ -65,7 +65,15 @@ class Test_Repo(common.TransactionCase):
                              'A nice subject',
                              'Marc Bidule',
                              '<marc.bidule@somewhere.com>')]
-        mock_fetch_head_time.side_effect = [100000.0, 100001.0, 100002.0]
+        self.commit_list = first_commit
+
+        def counter():
+            i = 100000
+            while True:
+                i += 1
+                yield i
+
+        mock_fetch_head_time.side_effect = counter()
 
         with patch('odoo.addons.runbot.models.repo.runbot_repo._git', new=self.mock_git_helper()):
             repo._create_pending_builds()
@@ -117,6 +125,7 @@ class Test_Repo(common.TransactionCase):
         self.assertEqual(branch_count, 1, 'No new branch should have been created')
 
         build = self.env['runbot.build'].search([('repo_id', '=', repo.id), ('branch_id', '=', branch.id), ('name', '=', 'b00b')])
+        self.assertEqual(len(build), 1)
         self.assertEqual(build.subject, 'Another subject')
         self.assertEqual(build.local_state, 'pending')
         self.assertFalse(build.local_result)
@@ -125,6 +134,23 @@ class Test_Repo(common.TransactionCase):
         self.assertEqual(previous_build.local_state, 'done', 'Previous pending build should be done')
         self.assertEqual(previous_build.local_result, 'skipped', 'Previous pending build result should be skipped')
 
+        self.commit_list = first_commit  # branch reseted hard to an old commit
+        builds = self.env['runbot.build'].search([('repo_id', '=', repo.id), ('branch_id', '=', branch.id), ('name', '=', 'd0d0caca')])
+        self.assertEqual(len(builds), 1)
+        with patch('odoo.addons.runbot.models.repo.runbot_repo._git', new=self.mock_git_helper()):
+            repo._create_pending_builds()
+
+        last_build = self.env['runbot.build'].search([], limit=1)
+        self.assertEqual(last_build.name, 'd0d0caca')
+        builds = self.env['runbot.build'].search([('repo_id', '=', repo.id), ('branch_id', '=', branch.id), ('name', '=', 'd0d0caca')])
+        self.assertEqual(len(builds), 2)
+        # self.assertEqual(last_build.duplicate_id, previous_build) False because previous_build is skipped
+        with patch('odoo.addons.runbot.models.repo.runbot_repo._git', new=self.mock_git_helper()):
+            other_repo._create_pending_builds()
+        builds = self.env['runbot.build'].search([('repo_id', '=', repo.id), ('branch_id', '=', branch.id), ('name', '=', 'd0d0caca')])
+        self.assertEqual(len(builds), 2)
+
+
     @skip('This test is for performances. It needs a lot of real branches in DB to mean something')
     @patch('odoo.addons.runbot.models.repo.runbot_repo._root')
     def test_repo_perf_find_new_commits(self, mock_root):