diff --git a/requirements.txt b/requirements.txt
index e42e3ca70..c017f4192 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,12 +7,12 @@ enum34;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' #
 jsonpatch>=1.1 # BSD
 keystoneauth1>=2.16.0 # Apache-2.0
 keystonemiddleware>=4.12.0 # Apache-2.0
-lxml>=2.3 # BSD
+lxml!=3.7.0,>=2.3 # BSD
 oslo.concurrency>=3.8.0 # Apache-2.0
 oslo.cache>=1.5.0 # Apache-2.0
 oslo.config!=3.18.0,>=3.14.0 # Apache-2.0
 oslo.context>=2.9.0 # Apache-2.0
-oslo.db!=4.13.1,!=4.13.2,>=4.11.0 # Apache-2.0
+oslo.db>=4.15.0 # Apache-2.0
 oslo.i18n>=2.1.0 # Apache-2.0
 oslo.log>=3.11.0 # Apache-2.0
 oslo.messaging>=5.14.0 # Apache-2.0
@@ -37,6 +37,6 @@ python-openstackclient>=3.3.0 # Apache-2.0
 six>=1.9.0 # MIT
 SQLAlchemy<1.1.0,>=1.0.10 # MIT
 stevedore>=1.17.1 # Apache-2.0
-taskflow>=1.26.0 # Apache-2.0
+taskflow>=2.7.0 # Apache-2.0
 WebOb>=1.6.0 # MIT
 WSME>=0.8 # MIT