diff --git a/runbot_merge/models/pull_requests.py b/runbot_merge/models/pull_requests.py
index 808733a7..51dee79f 100644
--- a/runbot_merge/models/pull_requests.py
+++ b/runbot_merge/models/pull_requests.py
@@ -1264,19 +1264,21 @@ class Commit(models.Model):
         # chances are low that we'll have more than one commit
         for c in self.search([('to_check', '=', True)]):
             try:
-                with self.env.cr:
-                    c.to_check = False
-                    st = json.loads(c.statuses)
-                    pr = PRs.search([('head', '=', c.sha)])
-                    if pr:
-                        pr._validate(st)
-                    # heads is a json-encoded mapping of reponame:head, so chances
-                    # are if a sha matches a heads it's matching one of the shas
-                    stagings = Stagings.search([('heads', 'ilike', c.sha)])
-                    if stagings:
-                        stagings._validate()
+                c.to_check = False
+                st = json.loads(c.statuses)
+                pr = PRs.search([('head', '=', c.sha)])
+                if pr:
+                    pr._validate(st)
+                # heads is a json-encoded mapping of reponame:head, so chances
+                # are if a sha matches a heads it's matching one of the shas
+                stagings = Stagings.search([('heads', 'ilike', c.sha)])
+                if stagings:
+                    stagings._validate()
             except Exception:
                 _logger.exception("Failed to apply commit %s (%s)", c, c.sha)
+                self.env.cr.rollback()
+            else:
+                self.env.cr.commit()
 
     _sql_constraints = [
         ('unique_sha', 'unique (sha)', 'no duplicated commit'),