diff --git a/Web/Authenticate/Rpxnow.hs b/Web/Authenticate/Rpxnow.hs
--- a/Web/Authenticate/Rpxnow.hs
+++ b/Web/Authenticate/Rpxnow.hs
@@ -40,6 +40,7 @@
 import qualified Data.Aeson.Types
 import qualified Data.Map as Map
 import Control.Applicative ((<$>), (<*>))
+import Network.TLS (TLSCertificateUsage (CertificateUsageAccept))
 
 -- | Information received from Rpxnow after a valid login.
 data Identifier = Identifier
@@ -74,7 +75,7 @@
                     [ ("Content-Type", "application/x-www-form-urlencoded")
                     ]
                 , requestBody = RequestBodyLBS body
-                , checkCerts = const $ return True
+                , checkCerts = const $ return CertificateUsageAccept
                 , proxy = Nothing
                 , rawBody = False
                 }
diff --git a/authenticate.cabal b/authenticate.cabal
--- a/authenticate.cabal
+++ b/authenticate.cabal
@@ -1,5 +1,5 @@
 name:            authenticate
-version:         0.9.1.3
+version:         0.9.1.4
 license:         BSD3
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>
@@ -16,7 +16,7 @@
 library
     build-depends:   base >= 4 && < 5,
                      aeson >= 0.3.1.1 && < 0.4,
-                     http-enumerator >= 0.6.5.2 && < 0.7,
+                     http-enumerator >= 0.6.5.4 && < 0.7,
                      tagsoup >= 0.6 && < 0.13,
                      failure >= 0.0.0 && < 0.2,
                      transformers >= 0.1 && < 0.3,
@@ -34,7 +34,8 @@
                      http-types >= 0.6 && < 0.7,
                      enumerator >= 0.4.7 && < 0.5,
                      blaze-builder >= 0.2 && < 0.4,
-                     attoparsec >= 0.8.5 && < 0.9,
+                     attoparsec >= 0.9   && < 0.10,
+                     tls >= 0.7 && < 0.8,
                      containers
     exposed-modules: Web.Authenticate.Rpxnow,
                      Web.Authenticate.OpenId,