diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Change log for "tls"
 
+## Version 2.4.3
+
+* A server checks clientAuth of ExtendedKeyUsage in a client
+  certificate on client authentication.
+
+## Version 2.4.2
+
+* The `Network.TLS.Extra.CipherCBC` module is added.
+  [#526](https://github.com/haskell-tls/hs-tls/pull/526)
+
 ## Version 2.4.1
 
 * Ensure same `supported_groups` before/after HRR.
diff --git a/Network/TLS/Handshake/Certificate.hs b/Network/TLS/Handshake/Certificate.hs
--- a/Network/TLS/Handshake/Certificate.hs
+++ b/Network/TLS/Handshake/Certificate.hs
@@ -3,13 +3,20 @@
     badCertificate,
     rejectOnException,
     verifyLeafKeyUsage,
+    verifyLeafKeyUsagePurpose,
     extractCAname,
 ) where
 
 import Control.Exception (SomeException)
 import Control.Monad (unless)
 import Control.Monad.State.Strict
-import Data.X509 (ExtKeyUsage (..), ExtKeyUsageFlag, extensionGet)
+import Data.X509 (
+    ExtExtendedKeyUsage (..),
+    ExtKeyUsage (..),
+    ExtKeyUsageFlag,
+    ExtKeyUsagePurpose (..),
+    extensionGet,
+ )
 
 import Network.TLS.Context.Internal
 import Network.TLS.Struct
@@ -46,6 +53,19 @@
         case extensionGet (certExtensions cert) of
             Nothing -> True -- unrestricted cert
             Just (ExtKeyUsage flags) -> any (`elem` validFlags) flags
+
+verifyLeafKeyUsagePurpose
+    :: MonadIO m => ExtKeyUsagePurpose -> CertificateChain -> m ()
+verifyLeafKeyUsagePurpose _ (CertificateChain []) = return ()
+verifyLeafKeyUsagePurpose validPurpose (CertificateChain (signed : _)) =
+    unless verified $
+        badCertificate $
+            "certificate is not allowed for " ++ show validPurpose
+  where
+    cert = getCertificate signed
+    verified = case extensionGet (certExtensions cert) of
+        Nothing -> True
+        Just (ExtExtendedKeyUsage purposes) -> validPurpose `elem` purposes
 
 extractCAname :: SignedCertificate -> DistinguishedName
 extractCAname cert = certSubjectDN $ getCertificate cert
diff --git a/Network/TLS/Handshake/Server/Common.hs b/Network/TLS/Handshake/Server/Common.hs
--- a/Network/TLS/Handshake/Server/Common.hs
+++ b/Network/TLS/Handshake/Server/Common.hs
@@ -15,7 +15,7 @@
 ) where
 
 import Control.Monad.State.Strict
-import Data.X509 (ExtKeyUsageFlag (..))
+import Data.X509 (ExtKeyUsageFlag (..), ExtKeyUsagePurpose (..))
 
 import Network.TLS.Context.Internal
 import Network.TLS.Credentials
@@ -151,7 +151,9 @@
                 (onClientCertificate (serverHooks sparams) certs)
                 rejectOnException
     case usage of
-        CertificateUsageAccept -> verifyLeafKeyUsage [KeyUsage_digitalSignature] certs
+        CertificateUsageAccept -> do
+            verifyLeafKeyUsage [KeyUsage_digitalSignature] certs
+            verifyLeafKeyUsagePurpose KeyUsagePurpose_ClientAuth certs
         CertificateUsageReject reason -> certificateRejected reason
 
     -- Remember cert chain for later use.
diff --git a/tls.cabal b/tls.cabal
--- a/tls.cabal
+++ b/tls.cabal
@@ -1,6 +1,6 @@
 cabal-version:      >=1.10
 name:               tls
-version:            2.4.2
+version:            2.4.3
 license:            BSD3
 license-file:       LICENSE
 copyright:          Vincent Hanquez <vincent@snarc.org>
@@ -138,7 +138,7 @@
         random >=1.2 && <1.4,
         serialise >=0.2 && <0.3,
         transformers >=0.5 && <0.7,
-        unix-time >=0.4.11 && <0.5,
+        unix-time >=0.4.11 && <0.6,
         zlib >=0.7 && <0.8
 
 executable tls-server