diff --git a/requirements.txt b/requirements.txt
index 772b5f1e..e097043f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -17,4 +17,4 @@ importlib-resources>=1.3; python_version < '3.9'
 truststore>=0.8.0; python_version >= '3.10'
 setuptools>=60.8.1; python_version >= '3.7'
 setuptools==59.6.0; python_version < '3.7'  # v59.6.0 is the last version to support Python 3.6
-telnetlib3>=2.0.4; python_version >= '3.7'
+telnetlib3>=2.0.4; python_version >= '3.7'  # 2.0.0 only support 3.7 and higher.