diff --git a/tcp_tests/requirements.txt b/tcp_tests/requirements.txt
index 83461ab..f7f9c9f 100644
--- a/tcp_tests/requirements.txt
+++ b/tcp_tests/requirements.txt
@@ -5,7 +5,7 @@
 paramiko
 six
 requests>=2.2.0
-oslo.config>=6.2.1 # Apache-2.0
+oslo.config>=6.2.1,<6.6.0 # Apache-2.0
 pytest>=2.9,<=3.2.5
 docker-py
 docker-compose==1.7.1