diff --git a/runbot/models/build.py b/runbot/models/build.py
index da2b8955..2479396f 100644
--- a/runbot/models/build.py
+++ b/runbot/models/build.py
@@ -729,6 +729,9 @@ class BuildResult(models.Model):
                 build._github_status()
             build._run_job()
 
+            if build.local_state == 'done':
+                self.env['runbot.commit.export'].search([('build_id', '=', build.id)]).unlink()
+
     def _run_job(self):
         # run job
         for build in self:
@@ -794,7 +797,7 @@ class BuildResult(models.Model):
             if build_export_path in exports:
                 self._log('_checkout', 'Multiple repo have same export path in build, some source may be missing for %s' % build_export_path, level='ERROR')
                 self._kill(result='ko')
-            exports[build_export_path] = commit.export()
+            exports[build_export_path] = commit.export(self)
 
         checkout_time = time.time() - start
         if checkout_time > 60:
diff --git a/runbot/models/commit.py b/runbot/models/commit.py
index 9a9da2bd..cb12b378 100644
--- a/runbot/models/commit.py
+++ b/runbot/models/commit.py
@@ -52,11 +52,11 @@ class Commit(models.Model):
                     module = os.path.basename(os.path.dirname(manifest_path))
                     yield (addons_path, module, manifest_file_name)
 
-    def export(self):
+    def export(self, build):
         """Export a git repo into a sources"""
         #  TODO add automated tests
         self.ensure_one()
-
+        self.env['runbot.commit.export'].create({'commit_id': self.id, 'build_id': build.id})
         export_path = self._source_path()
 
         if os.path.isdir(export_path):
@@ -228,3 +228,13 @@ class CommitStatus(models.Model):
                 self._cr.after('commit', send_github_status_async)
             else:
                 send_github_status(self.env)
+
+
+class CommitExport(models.Model):
+    _name = 'runbot.commit.export'
+    _description = 'Commit export'
+
+    build_id = fields.Many2one('runbot.build', index=True)
+    commit_id = fields.Many2one('runbot.commit')
+
+    host = fields.Char(related='build_id.host', store=True)
diff --git a/runbot/models/runbot.py b/runbot/models/runbot.py
index c99d5fec..c6430fad 100644
--- a/runbot/models/runbot.py
+++ b/runbot/models/runbot.py
@@ -315,10 +315,15 @@ class Runbot(models.AbstractModel):
             if self.pool._init:
                 return
             _logger.info('Source cleaning')
-            # we can remove a source only if no build are using them as name or rependency_ids aka as commit
+
+            cannot_be_deleted_path = set()
+            for commit in self.env['runbot.commit.export'].search([('host', '=', fqdn())]).mapped('commit_id'):
+                cannot_be_deleted_path.add(commit._source_path())
+
+
+            # the following part won't be usefull anymore once runbot.commit.export is populated
             cannot_be_deleted_builds = self.env['runbot.build'].search([('host', '=', fqdn()), ('local_state', '!=', 'done')])
             cannot_be_deleted_builds |= cannot_be_deleted_builds.mapped('params_id.builds_reference_ids')
-            cannot_be_deleted_path = set()
             for build in cannot_be_deleted_builds:
                 for build_commit in build.params_id.commit_link_ids:
                     cannot_be_deleted_path.add(build_commit.commit_id._source_path())
diff --git a/runbot/security/ir.model.access.csv b/runbot/security/ir.model.access.csv
index 3fec37f8..e906e7b5 100644
--- a/runbot/security/ir.model.access.csv
+++ b/runbot/security/ir.model.access.csv
@@ -114,3 +114,5 @@ access_runbot_dockerfile_admin,access_runbot_dockerfile_admin,runbot.model_runbo
 
 access_runbot_codeowner_admin,runbot_codeowner_admin,runbot.model_runbot_codeowner,runbot.group_runbot_admin,1,1,1,1
 access_runbot_codeowner_user,runbot_codeowner_user,runbot.model_runbot_codeowner,group_user,1,0,0,0
+
+access_runbot_commit_export_admin,runbot_commit_export_admin,runbot.model_runbot_commit_export,runbot.group_runbot_admin,1,1,1,1