diff --git a/README.rst b/README.rst
index 0626c713..0811218d 100644
--- a/README.rst
+++ b/README.rst
@@ -38,11 +38,13 @@ Some functionalities of ryu requires extra packages:
 - OF-Config requires lxml
 - NETCONF requires paramiko
 - BGP speaker (ssh console) requires paramiko
+- OVSDB support requires ovs  (Note: python 3.4 requires ovs>=2.6.0.dev0)
 
 If you want to use the functionalities, please install requirements::
 
     % pip install lxml
     % pip install paramiko
+    % pip install ovs
 
 
 Support
diff --git a/tools/pip-requires b/tools/pip-requires
index 637e1163..a59805b0 100644
--- a/tools/pip-requires
+++ b/tools/pip-requires
@@ -5,4 +5,3 @@ oslo.config>=1.15.0
 routes  # wsgi
 six>=1.4.0
 webob>=1.2  # wsgi
-ovs >=2.6.0.dev0