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
@@ -24,7 +24,6 @@
 import qualified Crypto.Cipher.RSA as RSA
 import qualified Crypto.Cipher.DSA as DSA
 
-import Data.Text.Lazy (unpack)
 import Data.Certificate.X509Cert (oidCommonName)
 
 #if defined(NOCERTVERIFY)
@@ -70,7 +69,7 @@
 					then certificateVerifyChain $ tail l
 					else return False
 	where
-		matchsysX509 (X509 cert _ _ _) (X509 syscert _ _ _) = do
+		matchsysX509 (X509 cert _ _ _ _) (X509 syscert _ _ _ _) = do
 			let x = certSubjectDN syscert
 			let y = certIssuerDN cert
 			x == y
@@ -79,7 +78,7 @@
 -- | verify a certificate against another one.
 -- the first certificate need to be signed by the second one for this function to succeed.
 certificateVerifyAgainst :: X509 -> X509 -> IO Bool
-certificateVerifyAgainst ux509@(X509 _ _ sigalg sig) (X509 scert _ _ _) = do
+certificateVerifyAgainst ux509@(X509 _ _ _ sigalg sig) (X509 scert _ _ _ _) = do
 	let f = verifyF sigalg pk
 	case f udata esig of
 		Right True -> return True
@@ -113,7 +112,7 @@
 			
 verifyF _ _ = (\_ _ -> Left "unexpected/wrong signature")
 
-dsaSHA1Verify pk a b = either (Left . show) (Right) $ DSA.verify asig SHA1.hash pk b
+dsaSHA1Verify pk _ b = either (Left . show) (Right) $ DSA.verify asig SHA1.hash pk b
 	where asig = (0,0) {- FIXME : need to work out how to get R/S from the bytestring a -}
 
 rsaVerify h hdesc pk a b = either (Left . show) (Right) $ RSA.verify h hdesc pk a b
@@ -124,10 +123,10 @@
 -- | Verify that the given certificate chain is application to the given fully qualified host name.
 certificateVerifyDomain :: String -> [X509] -> Bool
 certificateVerifyDomain _      []                  = False
-certificateVerifyDomain fqhn (X509 cert _ _ _:_) =
+certificateVerifyDomain fqhn (X509 cert _ _ _ _:_) =
 	case lookup oidCommonName $ certSubjectDN cert of
 		Nothing       -> False
-		Just (_, val) -> matchDomain (splitDot $ unpack val)
+		Just (_, val) -> matchDomain (splitDot val)
 	where
 		matchDomain l
 			| length (filter (== "") l) > 0 = False
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:             0.2.1
+Version:             0.2.2
 Description:
    a set of extra definitions, default values and helpers for tls.
 License:             BSD3
@@ -28,7 +28,7 @@
 
 Library
   Build-Depends:     base > 3 && < 5
-                   , tls >= 0.6.2 && < 0.7
+                   , tls >= 0.6.3 && < 0.7
                    , mtl
                    , network >= 2.3
                    , cryptohash >= 0.6
@@ -36,7 +36,7 @@
                    , vector
                    , crypto-api >= 0.5
                    , cryptocipher >= 0.2.5
-                   , certificate >= 0.7 && < 0.8
+                   , certificate >= 0.8.1 && < 0.9
                    , text >= 0.5 && < 1.0
   Exposed-modules:   Network.TLS.Extra
   other-modules:     Network.TLS.Extra.Certificate