diff --git a/master.cfg b/master.cfg
index ed1e1eb..38f102f 100644
--- a/master.cfg
+++ b/master.cfg
@@ -1385,7 +1385,7 @@ def load_config (c):
     c['slaves'] = [buildslave.BuildSlave (slave['name'], passwd[slave['name']],
                                           max_builds = 1,
                                           notify_on_missing = [ str (slave['admin']) ],
-                                          missing_timeout = 300,
+                                          missing_timeout = 600,
                                           properties = { 'jobs' : slave['jobs'] })
                    for slave in config['slaves']]