diff --git a/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py b/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
index 0d7d682c3..debf50f40 100755
--- a/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
+++ b/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
@@ -90,14 +90,14 @@ class Cert_5_1_05_RouterAddressTimeout(thread_cert.TestCase):
         self._setUpRouter1()
         self.simulator.go(200)
         self.nodes[ROUTER1].start()
-        self.simulator.go(15)
+        self.simulator.go(config.ROUTER_RESTORE_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER1].reset()
         self._setUpRouter1()
         self.simulator.go(300)
         self.nodes[ROUTER1].start()
-        self.simulator.go(15)
+        self.simulator.go(config.ROUTER_RESTORE_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
     def verify(self, pv):
diff --git a/tests/scripts/thread-cert/config.py b/tests/scripts/thread-cert/config.py
index 2d5d116fe..fc81f0d0c 100644
--- a/tests/scripts/thread-cert/config.py
+++ b/tests/scripts/thread-cert/config.py
@@ -138,6 +138,9 @@ SECURITY_POLICY = [672, 'onrc']
 
 LEADER_STARTUP_DELAY = 12
 ROUTER_STARTUP_DELAY = 10
+# See logic of RouterRoleRestorer
+# ((kMaxTxCount=6) - 1) * 1.1 * (kMulticastRetxDelay=5) + 2 + ROUTER_STARTUP_DELAY
+ROUTER_RESTORE_DELAY = 40
 LEADER_REBOOT_DELAY = 40
 ED_STARTUP_DELAY = 5
 BORDER_ROUTER_STARTUP_DELAY = 20