diff --git a/freezerclient/v1/client.py b/freezerclient/v1/client.py
index e396e5e..e52d5ed 100644
--- a/freezerclient/v1/client.py
+++ b/freezerclient/v1/client.py
@@ -138,7 +138,7 @@ class Client(object):
             self.opts = opts
 
         self.cert = cert
-        self.cacert = cacert
+        self.cacert = cacert or self.opts.os_cacert
         self._session = session
         verify = self.opts.os_cacert
         if self.opts.insecure: