diff --git a/certclient.py b/certclient.py
index 3490d43..ce8b842 100755
--- a/certclient.py
+++ b/certclient.py
@@ -20,6 +20,11 @@ parser.add_argument(
     dest='client_key',
     action='store',
     required=True)
+parser.add_argument(
+    '--csr',
+    dest='csr',
+    action='store',
+    required=True)
 parser.add_argument(
     '--server',
     dest='server',
@@ -30,7 +35,7 @@ FLAGS = parser.parse_args()
 
 class CertClient(object):
 
-  def __init__(self, server, ca_cert, client_cert, client_key):
+  def __init__(self, server, ca_cert, client_cert, client_key, csr):
     self._session = requests.Session()
     self._session.verify = ca_cert
     self._session.cert = (client_cert, client_key)
@@ -38,9 +43,11 @@ class CertClient(object):
       'Content-Type': 'application/x-pem-file',
     })
     self._server = server
+    self._csr = csr
 
   def Request(self):
-    self._session.post(self._server, data='foo')
+    with open(self._csr, 'r') as fh:
+      self._session.post(self._server, data=fh.read())
 
 
 def main():
@@ -48,7 +55,8 @@ def main():
       FLAGS.server,
       FLAGS.ca_cert,
       FLAGS.client_cert,
-      FLAGS.client_key)
+      FLAGS.client_key,
+      FLAGS.csr)
   client.Request()