diff --git a/runbot_merge/models/project.py b/runbot_merge/models/project.py
index e828d29b..57fc1a33 100644
--- a/runbot_merge/models/project.py
+++ b/runbot_merge/models/project.py
@@ -51,6 +51,15 @@ class Project(models.Model):
     freeze_id = fields.Many2one('runbot_merge.project.freeze', compute='_compute_freeze')
     freeze_reminder = fields.Text()
 
+    uniquifier = fields.Boolean(
+        default=True,
+        help="Whether to add a uniquifier commit on repositories without PRs"
+             " during staging. The lack of uniquifier can lead to CI conflicts"
+             " as github works off of commits, so it's possible for an"
+             " unrelated build to trigger a failure if somebody is a dummy and"
+             " includes repos they have no commit for."
+    )
+
     @api.depends('github_token')
     def _compute_identity(self):
         s = requests.Session()
diff --git a/runbot_merge/models/stagings_create.py b/runbot_merge/models/stagings_create.py
index 42b1aad5..7e083e0e 100644
--- a/runbot_merge/models/stagings_create.py
+++ b/runbot_merge/models/stagings_create.py
@@ -90,23 +90,11 @@ def try_staging(branch: Branch) -> Optional[Stagings]:
     heads = []
     commits = []
     for repo, it in staging_state.items():
-        if it.head != original_heads[repo]:
-            # if we staged something for that repo, just create a record for
-            # that commit, or flag existing one as to-recheck in case there are
-            # already statuses we want to propagate to the staging or something
-            env.cr.execute(
-                "INSERT INTO runbot_merge_commit (sha, to_check, statuses) "
-                "VALUES (%s, true, '{}') "
-                "ON CONFLICT (sha) DO UPDATE SET to_check=true "
-                "RETURNING id",
-                [it.head]
-            )
-            [commit] = [head] = env.cr.fetchone()
-        else:
-            # if we didn't stage anything for that repo, create a dummy commit
-            # (with a uniquifier to ensure we don't hit a previous version of
-            # the same) to ensure the staging head is new and we're building
-            # everything
+        if it.head == original_heads[repo] and branch.project_id.uniquifier:
+            # if we didn't stage anything for that repo and uniquification is
+            # enabled, create a dummy commit with a uniquifier to ensure we
+            # don't hit a previous version of the same to ensure the staging
+            # head is new and we're building everything
             project = branch.project_id
             uniquifier = base64.b64encode(os.urandom(12)).decode('ascii')
             dummy_head = it.repo.with_config(check=True).commit_tree(
@@ -135,6 +123,18 @@ For-Commit-Id: {it.head}
             )
             ([commit], [head]) = env.cr.fetchall()
             it.head = dummy_head
+        else:
+            # otherwise just create a record for that commit, or flag existing
+            # one as to-recheck in case there are already statuses we want to
+            # propagate to the staging or something
+            env.cr.execute(
+                "INSERT INTO runbot_merge_commit (sha, to_check, statuses) "
+                "VALUES (%s, true, '{}') "
+                "ON CONFLICT (sha) DO UPDATE SET to_check=true "
+                "RETURNING id",
+                [it.head]
+            )
+            [commit] = [head] = env.cr.fetchone()
 
         heads.append(fields.Command.create({
             'repository_id': repo.id,
diff --git a/runbot_merge/tests/test_multirepo.py b/runbot_merge/tests/test_multirepo.py
index 3ba105ca..dbae165c 100644
--- a/runbot_merge/tests/test_multirepo.py
+++ b/runbot_merge/tests/test_multirepo.py
@@ -87,9 +87,11 @@ def make_branch(repo, name, message, tree, protect=True):
         repo.protect(name)
     return c
 
-def test_stage_one(env, project, repo_a, repo_b, config):
+@pytest.mark.parametrize('uniquifier', [False, True])
+def test_stage_one(env, project, repo_a, repo_b, config, uniquifier):
     """ First PR is non-matched from A => should not select PR from B
     """
+    project.uniquifier = uniquifier
     project.batch_limit = 1
 
     with repo_a:
@@ -112,7 +114,10 @@ def test_stage_one(env, project, repo_a, repo_b, config):
     assert pra_id.state == 'ready'
     assert pra_id.staging_id
     assert repo_a.commit('staging.master').message.startswith('commit_A_00')
-    assert repo_b.commit('staging.master').message.startswith('force rebuild')
+    if uniquifier:
+        assert repo_b.commit('staging.master').message.startswith('force rebuild')
+    else:
+        assert repo_b.commit('staging.master').message == 'initial'
 
     prb_id = to_pr(env, pr_b)
     assert prb_id.state == 'ready'
diff --git a/runbot_merge/views/runbot_merge_project.xml b/runbot_merge/views/runbot_merge_project.xml
index 4795b502..5aa49d47 100644
--- a/runbot_merge/views/runbot_merge_project.xml
+++ b/runbot_merge/views/runbot_merge_project.xml
@@ -32,6 +32,7 @@
                             <field name="secret"/>
                         </group>
                         <group>
+                            <field name="uniquifier"/>
                             <field name="ci_timeout"/>
                             <field name="batch_limit"/>
                         </group>