diff --git a/requirements.txt b/requirements.txt
index ad7beae7..46af08f9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@
 # adding a new feature to oslo.utils means adding a new dependency,
 # that is a likely indicator that the feature belongs somewhere else.
 
-pbr>=2.0.0 # Apache-2.0
+pbr!=2.1.0,>=2.0.0 # Apache-2.0
 six>=1.9.0 # MIT
 funcsigs>=0.4;python_version=='2.7' or python_version=='2.6' # Apache-2.0
 iso8601>=0.1.11 # MIT