diff --git a/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py b/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
index e54cff75b..019dada46 100755
--- a/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
+++ b/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
@@ -42,7 +42,7 @@ class Cert_8_1_02_Commissioning(unittest.TestCase):
 
         self.nodes = {}
         for i in range(1,3):
-            self.nodes[i] = node.Node(i)
+            self.nodes[i] = node.Node(i, simulator=self.simulator)
 
         self.nodes[COMMISSIONER].set_panid(0xface)
         self.nodes[COMMISSIONER].set_mode('rsdn')
diff --git a/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py b/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
index 08b77d8a0..8a8570083 100755
--- a/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
+++ b/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
@@ -43,7 +43,7 @@ class Cert_8_2_01_JoinerRouter(unittest.TestCase):
 
         self.nodes = {}
         for i in range(1,4):
-            self.nodes[i] = node.Node(i)
+            self.nodes[i] = node.Node(i, simulator=self.simulator)
 
         self.nodes[COMMISSIONER].set_panid(0xface)
         self.nodes[COMMISSIONER].set_mode('rsdn')