diff --git a/runbot/models/build.py b/runbot/models/build.py
index 8749f0bc..675708fb 100644
--- a/runbot/models/build.py
+++ b/runbot/models/build.py
@@ -806,6 +806,9 @@ class runbot_build(models.Model):
         elif build.local_state in ['testing', 'running']:
             build.write({'local_state': 'deathrow'})
             build._log('_ask_kill', 'Killing build %s, requested by %s (user #%s)' % (build.dest, user.name, uid))
+            for child in build.children_ids: # should we filter build that are target of a duplicate_id?
+                if not build.duplicate_id and build.local_state != 'done':
+                    child._ask_kill()
 
     def _cmd(self):  # why not remove build.modules output ?
         """Return a tuple describing the command to start the build