diff --git a/test-requirements.txt b/test-requirements.txt
index 196387c..c6bf5ca 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,6 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 hacking>=1.1.0,<1.2.0 # Apache-2.0
+pycodestyle<2.6.0 # Expat
 mock>=2.0.0 # BSD
 coverage!=4.4,>=4.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0