diff --git a/requirements.txt b/requirements.txt
index 74ee6a636..e01ff13f6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ pecan>=1.0.0 # BSD
 pycrypto>=2.6 # Public Domain
 pyOpenSSL>=0.14 # Apache-2.0
 ldap3>=0.9.8.2 # LGPLv3
-keystonemiddleware>=4.0.0 # Apache-2.0
+keystonemiddleware!=4.1.0,>=4.0.0 # Apache-2.0
 six>=1.9.0 # MIT
 SQLAlchemy<1.1.0,>=1.0.10 # MIT
 stevedore>=1.5.0 # Apache-2.0