diff --git a/forwardport/tests/test_simple.py b/forwardport/tests/test_simple.py
index d10d5fcb..3377bfa4 100644
--- a/forwardport/tests/test_simple.py
+++ b/forwardport/tests/test_simple.py
@@ -6,7 +6,7 @@ from datetime import datetime, timedelta
 
 import pytest
 
-from utils import seen, Commit, make_basic, REF_PATTERN, MESSAGE_TEMPLATE, validate_all
+from utils import seen, Commit, make_basic, REF_PATTERN, MESSAGE_TEMPLATE, validate_all, part_of
 
 FMT = '%Y-%m-%d %H:%M:%S'
 FAKE_PREV_WEEK = (datetime.now() + timedelta(days=1)).strftime(FMT)
@@ -198,7 +198,7 @@ More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port
     old_b = prod.read_tree(b_head)
     head_b = prod.commit('b')
     assert head_b.message == message_template % pr1.number
-    assert prod.commit(head_b.parents[0]).message == 'p_0\n\nX-original-commit: %s' % p_0_merged
+    assert prod.commit(head_b.parents[0]).message == part_of(f'p_0\n\nX-original-commit: {p_0_merged}', pr1, separator='\n')
     b_tree = prod.read_tree(head_b)
     assert b_tree == {
         **old_b,
@@ -207,7 +207,7 @@ More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port
     old_c = prod.read_tree(c_head)
     head_c = prod.commit('c')
     assert head_c.message == message_template % pr2.number
-    assert prod.commit(head_c.parents[0]).message == 'p_0\n\nX-original-commit: %s' % p_0_merged
+    assert prod.commit(head_c.parents[0]).message == part_of(f'p_0\n\nX-original-commit: {p_0_merged}', pr2, separator='\n')
     c_tree = prod.read_tree(head_c)
     assert c_tree == {
         **old_c,
diff --git a/mergebot_test_utils/utils.py b/mergebot_test_utils/utils.py
index ba37fbc1..0cadbc11 100644
--- a/mergebot_test_utils/utils.py
+++ b/mergebot_test_utils/utils.py
@@ -130,3 +130,8 @@ def to_pr(env, pr):
         ('repository.name', '=', pr.repo.name),
         ('number', '=', pr.number),
     ])
+
+def part_of(label, pr_id, *, separator='\n\n'):
+    """ Adds the "part-of" pseudo-header in the footer.
+    """
+    return f'{label}{separator}Part-of: {pr_id.display_name}'
diff --git a/runbot_merge/models/pull_requests.py b/runbot_merge/models/pull_requests.py
index c58e3c34..84233d0c 100644
--- a/runbot_merge/models/pull_requests.py
+++ b/runbot_merge/models/pull_requests.py
@@ -1335,18 +1335,28 @@ class PullRequests(models.Model):
         """
         return Message.from_message(message)
 
+    def _is_mentioned(self, message, *, full_reference=False):
+        """Returns whether ``self`` is mentioned in ``message```
+
+        :param str | PullRequest message:
+        :param bool full_reference: whether the repository name must be present
+        :rtype: bool
+        """
+        if full_reference:
+            pattern = fr'\b{re.escape(self.display_name)}\b'
+        else:
+            repository = self.repository.name # .replace('/', '\\/')
+            pattern = fr'( |\b{repository})#{self.number}\b'
+        return bool(re.search(pattern, message if isinstance(message, str) else message.message))
+
     def _build_merge_message(self, message, related_prs=()):
         # handle co-authored commits (https://help.github.com/articles/creating-a-commit-with-multiple-authors/)
         m = self._parse_commit_message(message)
-        pattern = r'( |{repository})#{pr.number}\b'.format(
-            pr=self,
-            repository=self.repository.name.replace('/', '\\/')
-        )
-        if not re.search(pattern, m.body):
+        if not self._is_mentioned(message):
             m.body += '\n\ncloses {pr.display_name}'.format(pr=self)
 
         for r in related_prs:
-            if r.display_name not in m.body:
+            if not r._is_mentioned(message, full_reference=True):
                 m.headers.add('Related', r.display_name)
 
         if self.reviewed_by:
@@ -1354,6 +1364,17 @@ class PullRequests(models.Model):
 
         return m
 
+    def _add_self_references(self, commits):
+        """Adds a footer reference to ``self`` to all ``commits`` if they don't
+        already refer to the PR.
+        """
+        for c in (c['commit'] for c in commits):
+            if not self._is_mentioned(c['message']):
+                m = self._parse_commit_message(c['message'])
+                m.headers.pop('Part-Of', None)
+                m.headers.add('Part-Of', self.display_name)
+                c['message'] = str(m)
+
     def _stage(self, gh, target, related_prs=()):
         # nb: pr_commits is oldest to newest so pr.head is pr_commits[-1]
         _, prdict = gh.pr(self.number)
@@ -1395,13 +1416,15 @@ class PullRequests(models.Model):
         # on top of target
         msg = self._build_merge_message(commits[-1]['commit']['message'], related_prs=related_prs)
         commits[-1]['commit']['message'] = str(msg)
+        self._add_self_references(commits[:-1])
         head, mapping = gh.rebase(self.number, target, commits=commits)
         self.commits_map = json.dumps({**mapping, '': head})
         return head
 
     def _stage_rebase_merge(self, gh, target, commits, related_prs=()):
-        msg = self._build_merge_message(self, related_prs=related_prs)
+        self._add_self_references(commits)
         h, mapping = gh.rebase(self.number, target, reset=True, commits=commits)
+        msg = self._build_merge_message(self, related_prs=related_prs)
         merge_head = gh.merge(h, target, str(msg))['sha']
         self.commits_map = json.dumps({**mapping, '': merge_head})
         return merge_head
diff --git a/runbot_merge/tests/test_basic.py b/runbot_merge/tests/test_basic.py
index 1f0b08a2..17b011ba 100644
--- a/runbot_merge/tests/test_basic.py
+++ b/runbot_merge/tests/test_basic.py
@@ -9,7 +9,8 @@ import pytest
 from lxml import html
 
 import odoo
-from utils import _simple_init, seen, re_matches, get_partner, Commit, pr_page, to_pr
+from utils import _simple_init, seen, re_matches, get_partner, Commit, pr_page, to_pr, part_of
+
 
 @pytest.fixture
 def repo(env, project, make_repo, users, setreviewers):
@@ -642,13 +643,17 @@ def test_ff_failure_batch(env, repo, users, config):
         C.post_comment('hansen r+ rebase-merge', config['role_reviewer']['token'])
     env.run_crons()
 
+    pr_a = to_pr(env, A)
+    pr_b = to_pr(env, B)
+    pr_c = to_pr(env, C)
+
     messages = [
         c['commit']['message']
         for c in repo.log('heads/staging.master')
     ]
-    assert 'a2' in messages
-    assert 'b2' in messages
-    assert 'c2' in messages
+    assert part_of('a2', pr_a) in messages
+    assert part_of('b2', pr_b) in messages
+    assert part_of('c2', pr_c) in messages
 
     # block FF
     with repo:
@@ -676,9 +681,9 @@ def test_ff_failure_batch(env, repo, users, config):
     reviewer = get_partner(env, users["reviewer"]).formatted_email
     assert messages == {
         'initial', 'NO!',
-        'a1', 'a2', 'A\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, A.number, reviewer),
-        'b1', 'b2', 'B\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, B.number, reviewer),
-        'c1', 'c2', 'C\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, C.number, reviewer),
+        part_of('a1', pr_a), part_of('a2', pr_a), f'A\n\ncloses {pr_a.display_name}\n\nSigned-off-by: {reviewer}',
+        part_of('b1', pr_b), part_of('b2', pr_b), f'B\n\ncloses {pr_b.display_name}\n\nSigned-off-by: {reviewer}',
+        part_of('c1', pr_c), part_of('c2', pr_c), f'C\n\ncloses {pr_c.display_name}\n\nSigned-off-by: {reviewer}',
     }
 
 class TestPREdition:
@@ -1427,14 +1432,15 @@ class TestMergeMethod:
             prx.post_comment('hansen r+ rebase-merge', config['role_reviewer']['token'])
         env.run_crons()
 
+        pr_id = to_pr(env, prx)
         # create a dag (msg:str, parents:set) from the log
         staging = log_to_node(repo.log('heads/staging.master'))
         # then compare to the dag version of the right graph
         nm2 = node('M2', node('M1', node('M0')))
-        nb1 = node('B1', node('B0', nm2))
+        nb1 = node(part_of('B1', pr_id), node(part_of('B0', pr_id), nm2))
         reviewer = get_partner(env, users["reviewer"]).formatted_email
         merge_head = (
-            'title\n\nbody\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, prx.number, reviewer),
+            f'title\n\nbody\n\ncloses {pr_id.display_name}\n\nSigned-off-by: {reviewer}',
             frozenset([nm2, nb1])
         )
         expected = (re_matches('^force rebuild'), frozenset([merge_head]))
@@ -1504,13 +1510,14 @@ class TestMergeMethod:
             prx.post_comment('hansen r+ rebase-ff', config['role_reviewer']['token'])
         env.run_crons()
 
+        pr_id = to_pr(env, prx)
         # create a dag (msg:str, parents:set) from the log
         staging = log_to_node(repo.log('heads/staging.master'))
         # then compare to the dag version of the right graph
         nm2 = node('M2', node('M1', node('M0')))
         reviewer = get_partner(env, users["reviewer"]).formatted_email
-        nb1 = node('B1\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, prx.number, reviewer),
-                   node('B0', nm2))
+        nb1 = node(f'B1\n\ncloses {pr_id.display_name}\n\nSigned-off-by: {reviewer}',
+                   node(part_of('B0', pr_id), nm2))
         expected = node(re_matches('^force rebuild'), nb1)
         assert staging == expected
 
@@ -2358,12 +2365,6 @@ class TestBatching(object):
             )
         return pr
 
-    def _get(self, env, repo, number):
-        return env['runbot_merge.pull_requests'].search([
-            ('repository.name', '=', repo.name),
-            ('number', '=', number),
-        ])
-
     def test_staging_batch(self, env, repo, users, config):
         """ If multiple PRs are ready for the same target at the same point,
         they should be staged together
@@ -2376,9 +2377,9 @@ class TestBatching(object):
             pr2 = self._pr(repo, 'PR2', [{'c': 'CCC'}, {'d': 'DDD'}], user=config['role_user']['token'], reviewer=config['role_reviewer']['token'])
         env.run_crons()
 
-        pr1 = self._get(env, repo, pr1.number)
+        pr1 = to_pr(env, pr1)
         assert pr1.staging_id
-        pr2 = self._get(env, repo, pr2.number)
+        pr2 = to_pr(env, pr2)
         assert pr1.staging_id
         assert pr2.staging_id
         assert pr1.staging_id == pr2.staging_id
@@ -2387,16 +2388,19 @@ class TestBatching(object):
         staging = log_to_node(log)
         reviewer = get_partner(env, users["reviewer"]).formatted_email
         p1 = node(
-            'title PR1\n\nbody PR1\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, pr1.number, reviewer),
+            'title PR1\n\nbody PR1\n\ncloses {}\n\nSigned-off-by: {}'.format(pr1.display_name, reviewer),
             node('initial'),
-            node('commit_PR1_01', node('commit_PR1_00', node('initial')))
+            node(part_of('commit_PR1_01', pr1), node(part_of('commit_PR1_00', pr1), node('initial')))
         )
         p2 = node(
-            'title PR2\n\nbody PR2\n\ncloses {}#{}\n\nSigned-off-by: {}'.format(repo.name, pr2.number, reviewer),
+            'title PR2\n\nbody PR2\n\ncloses {}\n\nSigned-off-by: {}'.format(pr2.display_name, reviewer),
             p1,
-            node('commit_PR2_01', node('commit_PR2_00', p1))
+            node(part_of('commit_PR2_01', pr2), node(part_of('commit_PR2_00', pr2), p1))
         )
         expected = (re_matches('^force rebuild'), frozenset([p2]))
+        import pprint
+        pprint.pprint(staging)
+        pprint.pprint(expected)
         assert staging == expected
 
     def test_staging_batch_norebase(self, env, repo, users, config):
@@ -2413,10 +2417,10 @@ class TestBatching(object):
             pr2.post_comment('hansen merge', config['role_reviewer']['token'])
         env.run_crons()
 
-        pr1 = self._get(env, repo, pr1.number)
+        pr1 = to_pr(env, pr1)
         assert pr1.staging_id
         assert pr1.merge_method == 'merge'
-        pr2 = self._get(env, repo, pr2.number)
+        pr2 = to_pr(env, pr2)
         assert pr2.merge_method == 'merge'
         assert pr1.staging_id
         assert pr2.staging_id
@@ -2452,9 +2456,9 @@ class TestBatching(object):
             pr2 = self._pr(repo, 'PR2', [{'c': 'CCC'}], user=config['role_user']['token'], reviewer=config['role_reviewer']['token'])
         env.run_crons()
 
-        pr1 = self._get(env, repo, pr1.number)
+        pr1 = to_pr(env, pr1)
         assert pr1.staging_id
-        pr2 = self._get(env, repo, pr2.number)
+        pr2 = to_pr(env, pr2)
         assert pr1.staging_id
         assert pr2.staging_id
         assert pr1.staging_id == pr2.staging_id
@@ -2485,7 +2489,7 @@ class TestBatching(object):
             pr11.post_comment('hansen priority=1', config['role_reviewer']['token'])
             pr12.post_comment('hansen priority=1', config['role_reviewer']['token'])
 
-        pr21, pr22, pr11, pr12 = prs = [self._get(env, repo, pr.number) for pr in [pr21, pr22, pr11, pr12]]
+        pr21, pr22, pr11, pr12 = prs = [to_pr(env, pr) for pr in [pr21, pr22, pr11, pr12]]
         assert pr21.priority == pr22.priority == 2
         assert pr11.priority == pr12.priority == 1
 
@@ -2514,7 +2518,7 @@ class TestBatching(object):
         # stage PR1
         env.run_crons()
         p_11, p_12, p_21, p_22 = \
-            [self._get(env, repo, pr.number) for pr in [pr11, pr12, pr21, pr22]]
+            [to_pr(env, pr) for pr in [pr11, pr12, pr21, pr22]]
         assert not p_21.staging_id or p_22.staging_id
         assert p_11.staging_id and p_12.staging_id
         assert p_11.staging_id == p_12.staging_id
@@ -2524,7 +2528,7 @@ class TestBatching(object):
         with repo:
             pr01 = self._pr(repo, 'Urgent1', [{'n': 'n'}, {'o': 'o'}], user=config['role_user']['token'], reviewer=None, statuses=[])
             pr01.post_comment('hansen priority=0 rebase-merge', config['role_reviewer']['token'])
-        p_01 = self._get(env, repo, pr01.number)
+        p_01 = to_pr(env, pr01)
         assert p_01.state == 'opened'
         assert p_01.priority == 0
 
@@ -2544,9 +2548,9 @@ class TestBatching(object):
             repo.make_ref('heads/master', m)
 
             pr1 = self._pr(repo, 'PR1', [{'a': 'AAA'}, {'b': 'BBB'}], user=config['role_user']['token'], reviewer=config['role_reviewer']['token'])
-            p_1 = self._get(env, repo, pr1.number)
+            p_1 = to_pr(env, pr1)
             pr2 = self._pr(repo, 'PR2', [{'a': 'some content', 'c': 'CCC'}, {'d': 'DDD'}], user=config['role_user']['token'], reviewer=config['role_reviewer']['token'])
-            p_2 = self._get(env, repo, pr2.number)
+            p_2 = to_pr(env, pr2)
         env.run_crons()
 
         st = env['runbot_merge.stagings'].search([])
@@ -2570,7 +2574,7 @@ class TestBatching(object):
 
         # TODO: maybe just deactivate stagings instead of deleting them when canceling?
         assert not p_1.staging_id
-        assert self._get(env, repo, pr0.number).staging_id
+        assert to_pr(env, pr0).staging_id
 
     def test_urgent_failed(self, env, repo, config):
         """ Ensure pr[p=0,state=failed] don't get picked up
@@ -2581,13 +2585,13 @@ class TestBatching(object):
 
             pr21 = self._pr(repo, 'PR1', [{'a': 'AAA'}, {'b': 'BBB'}], user=config['role_user']['token'], reviewer=config['role_reviewer']['token'])
 
-        p_21 = self._get(env, repo, pr21.number)
+        p_21 = to_pr(env, pr21)
 
         # no statuses run on PR0s
         with repo:
             pr01 = self._pr(repo, 'Urgent1', [{'n': 'n'}, {'o': 'o'}], user=config['role_user']['token'], reviewer=None, statuses=[])
             pr01.post_comment('hansen priority=0', config['role_reviewer']['token'])
-        p_01 = self._get(env, repo, pr01.number)
+        p_01 = to_pr(env, pr01)
         p_01.state = 'error'
 
         env.run_crons()