diff --git a/runbot/models/branch.py b/runbot/models/branch.py
index 94e89049..977300b6 100644
--- a/runbot/models/branch.py
+++ b/runbot/models/branch.py
@@ -61,13 +61,17 @@ class Branch(models.Model):
             if branch.is_pr:
                 _, name = branch.pull_head_name.split(':')
                 if branch.pull_head_remote_id:
-                    branch.reference_name = name
+                    reference_name = name
                 else:
-                    branch.reference_name = branch.pull_head_name  # repo is not known, not in repo list must be an external pr, so use complete label
+                    reference_name = branch.pull_head_name  # repo is not known, not in repo list must be an external pr, so use complete label
                     #if ':patch-' in branch.pull_head_name:
                     #    branch.reference_name = '%s~%s' % (branch.pull_head_name, branch.name)
             else:
-                branch.reference_name = branch.name
+                reference_name = branch.name
+            forced_version = branch.remote_id.repo_id.single_version  # we don't add a depend on repo.single_version to avoid mass recompute of existing branches
+            if forced_version and not reference_name.startswith(f'{forced_version.name}-'):
+                reference_name = f'{forced_version.name}---{reference_name}'
+            branch.reference_name = reference_name
 
     @api.depends('name')
     def _compute_branch_infos(self, pull_info=None):
diff --git a/runbot/models/repo.py b/runbot/models/repo.py
index a7039241..41f130e7 100644
--- a/runbot/models/repo.py
+++ b/runbot/models/repo.py
@@ -242,6 +242,7 @@ class Repo(models.Model):
     last_processed_hook_time = fields.Float('Last processed hook time')
     get_ref_time = fields.Float('Last refs db update', compute='_compute_get_ref_time')
     trigger_ids = fields.Many2many('runbot.trigger', relation='runbot_trigger_triggers', readonly=True)
+    single_version = fields.Many2one('runbot.version', "Single version", help="Limit the repo to a single version for non versionned repo")
     forbidden_regex = fields.Char('Forbidden regex', help="Regex that forid bundle creation if branch name is matching", tracking=True)
     invalid_branch_message = fields.Char('Forbidden branch message', tracking=True)
 
diff --git a/runbot/views/repo_views.xml b/runbot/views/repo_views.xml
index 2033f873..06d8d1f3 100644
--- a/runbot/views/repo_views.xml
+++ b/runbot/views/repo_views.xml
@@ -85,6 +85,7 @@
                 <field name="mode"/>
                 <field name="forbidden_regex"/>
                 <field name="invalid_branch_message"/>
+                <field name="single_version"/>
                 <field name="remote_ids">
                   <tree string="Remotes" editable="bottom">
                     <field name="name"/>