diff --git a/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py b/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
index 47675695a..9c84f1b1d 100755
--- a/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
+++ b/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
@@ -109,7 +109,7 @@ class Cert_5_6_5_NetworkDataRegisterAfterAttachRouter(thread_cert.TestCase):
             if addr[0:3] == '200':
                 self.assertTrue(self.nodes[LEADER].ping(addr))
 
-        self.nodes[ROUTER].add_prefix('2001:2:0:3::/64', 'pacs')
+        self.nodes[ROUTER].add_prefix('2001:2:0:3::/64', 'paos')
         self.nodes[ROUTER].register_netdata()
 
         # Set lowpan context of sniffer
diff --git a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
index c92a90dd0..2dd5235d4 100755
--- a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
+++ b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
@@ -109,7 +109,7 @@ class Cert_5_6_6_NetworkDataExpiration(thread_cert.TestCase):
             if addr[0:3] == '200':
                 self.assertTrue(self.nodes[LEADER].ping(addr))
 
-        self.nodes[ROUTER].add_prefix('2001:2:0:3::/64', 'pacs')
+        self.nodes[ROUTER].add_prefix('2001:2:0:3::/64', 'paos')
         self.nodes[ROUTER].register_netdata()
 
         # Set lowpan context of sniffer