diff --git a/tests/scripts/thread-cert/requirements.txt b/tests/scripts/thread-cert/requirements.txt
index bd302c3eb..6de8b89b9 100644
--- a/tests/scripts/thread-cert/requirements.txt
+++ b/tests/scripts/thread-cert/requirements.txt
@@ -1,4 +1,4 @@
 enum34==1.1.2
 ipaddress==1.0.16
 pexpect==4.0.1
-pycryptodome==3.4.3
+pycryptodome==3.6.6