diff --git a/Examples/RetrieveCertificate.hs b/Examples/RetrieveCertificate.hs
--- a/Examples/RetrieveCertificate.hs
+++ b/Examples/RetrieveCertificate.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE ScopedTypeVariables, DeriveDataTypeable #-}
+{-# LANGUAGE ScopedTypeVariables, DeriveDataTypeable, ViewPatterns #-}
 
 import Network.TLS
 import Network.TLS.Extra
@@ -6,6 +6,7 @@
 import Data.Char
 import Data.IORef
 import Data.Time.Clock
+import Data.Certificate.X509
 
 import System.IO
 import Control.Monad
@@ -47,7 +48,7 @@
 	{ destination = "localhost" &= help "destination address to connect to" &= typ "address"
 	, port        = "443"       &= help "destination port to connect to" &= typ "port"
 	, chain       = False       &= help "also output the chain of certificate used"
-	, output      = "pem"       &= help "define the format of output (PEM by default)" &= typ "format"
+	, output      = "simple"    &= help "define the format of output (full, pem, default: simple)" &= typ "format"
 	, verify      = False       &= help "verify the chain received with the trusted system certificates"
 	, verifyFQDN  = ""          &= help "verify the chain against a specific fully qualified domain name (e.g. web.example.com)" &= explicit &= name "verify-domain-name"
 	} &= summary "RetrieveCertificate remotely for SSL/TLS protocol"
@@ -55,8 +56,13 @@
 		[ "Retrieve the remote certificate and optionally its chain from a remote destination"
 		]
 
-showCert _ cert =
-	putStrLn $ show cert
+showCert "full" cert = putStrLn $ show cert
+
+showCert _ (x509Cert -> cert)  = do
+	putStrLn ("serial:   " ++ (show $ certSerial cert))
+	putStrLn ("issuer:   " ++ (show $ certIssuerDN cert))
+	putStrLn ("subject:  " ++ (show $ certSubjectDN cert))
+	putStrLn ("validity: " ++ (show $ fst $ certValidity cert) ++ " to " ++ (show $ snd $ certValidity cert))
 
 main = do
 	a <- cmdArgs progArgs
diff --git a/Examples/Stunnel.hs b/Examples/Stunnel.hs
--- a/Examples/Stunnel.hs
+++ b/Examples/Stunnel.hs
@@ -282,5 +282,5 @@
 main = do
 	x <- cmdArgsRun mode
 	case x of
-		Client _ _ _ _ _ _ -> doClient x
-		Server _ _ _ _ _ _ _ _ -> doServer x
+		Client {} -> doClient x
+		Server {} -> doServer x
diff --git a/Network/TLS/Extra/Certificate.hs b/Network/TLS/Extra/Certificate.hs
--- a/Network/TLS/Extra/Certificate.hs
+++ b/Network/TLS/Extra/Certificate.hs
@@ -33,14 +33,20 @@
 
 import Data.Time.Calendar
 import Data.List (find)
+import Data.Maybe (fromMaybe)
 
--- | combine many certificates checking function together.
--- if one check fail, the whole sequence of checking is cuted short and return the
--- reject reason.
+#if defined(NOCERTVERIFY)
+
+import System.IO (hPutStrLn, stderr)
+
+#endif
+
+-- | Returns 'CertificateUsageAccept' if all the checks pass, or the first 
+--   failure.
 certificateChecks :: [ [X509] -> IO TLSCertificateUsage ] -> [X509] -> IO TLSCertificateUsage
 certificateChecks checks x509s = do
-	r <- sequence $ map (\c -> c x509s) checks
-	return $ maybe CertificateUsageAccept id $ find ((/=) CertificateUsageAccept) r
+	r <- mapM (\c -> c x509s) checks
+	return $ fromMaybe CertificateUsageAccept $ find (CertificateUsageAccept /=) r
 
 #if defined(NOCERTVERIFY)
 
@@ -52,8 +58,8 @@
  - for now, print a big fat warning (better than nothing) and returns true  -}
 certificateVerifyChain_ :: [X509] -> IO TLSCertificateUsage
 certificateVerifyChain_ _ = do
-	putStrLn "****************** certificate verify chain doesn't yet work on your platform **********************"
-	putStrLn "please consider contributing to the certificate package to fix this issue"
+	hPutStrLn stderr "****************** certificate verify chain doesn't yet work on your platform **********************"
+	hPutStrLn stderr "please consider contributing to the certificate package to fix this issue"
 	return CertificateUsageAccept
 
 #else
@@ -113,7 +119,7 @@
 		esig  = B.pack sig
 		pk    = certPubKey scert
 
--- | returns if this certificate is self signed.
+-- | Is this certificate self signed?
 certificateSelfSigned :: X509 -> Bool
 certificateSelfSigned x509 = certMatchDN x509 x509
 
diff --git a/tls-extra.cabal b/tls-extra.cabal
--- a/tls-extra.cabal
+++ b/tls-extra.cabal
@@ -1,5 +1,5 @@
 Name:                tls-extra
-Version:             0.4.3
+Version:             0.4.4
 Description:
    a set of extra definitions, default values and helpers for tls.
 License:             BSD3
@@ -36,7 +36,7 @@
                    , vector
                    , crypto-api >= 0.5
                    , cryptocipher >= 0.3.0
-                   , certificate >= 1.1.0 && < 1.2.0
+                   , certificate >= 1.1.1 && < 1.2.0
                    , text >= 0.5 && < 1.0
                    , time
   Exposed-modules:   Network.TLS.Extra
@@ -46,7 +46,7 @@
                      Network.TLS.Extra.Connection
                      Network.TLS.Extra.Thread
   ghc-options:       -Wall -fno-warn-missing-signatures
-  if os(windows) || os(osx)
+  if os(windows)
     cpp-options:     -DNOCERTVERIFY
 
 Executable           stunnel
@@ -101,6 +101,7 @@
                    , HUnit
                    , QuickCheck >= 2
                    , bytestring
+                   , cprng-aes >= 0.2.3
   else
     Buildable:       False