diff --git a/include/openssl/tls1.h b/include/openssl/tls1.h
index 854b83336c..500a6374b9 100644
--- a/include/openssl/tls1.h
+++ b/include/openssl/tls1.h
@@ -140,13 +140,13 @@ extern "C" {
 # define TLSEXT_TYPE_session_ticket              35
 
 /* As defined for TLS1.3 */
-# define TLSEXT_TYPE_key_share                   40
 # define TLSEXT_TYPE_psk                         41
 # define TLSEXT_TYPE_early_data                  42
 # define TLSEXT_TYPE_supported_versions          43
 # define TLSEXT_TYPE_cookie                      44
 # define TLSEXT_TYPE_psk_kex_modes               45
 # define TLSEXT_TYPE_certificate_authorities     47
+# define TLSEXT_TYPE_key_share                   51
 
 /* Temporary extension type */
 # define TLSEXT_TYPE_renegotiate                 0xff01
diff --git a/util/perl/TLSProxy/Message.pm b/util/perl/TLSProxy/Message.pm
index 1777e245d0..d55486de8c 100644
--- a/util/perl/TLSProxy/Message.pm
+++ b/util/perl/TLSProxy/Message.pm
@@ -74,7 +74,7 @@ use constant {
     EXT_ENCRYPT_THEN_MAC => 22,
     EXT_EXTENDED_MASTER_SECRET => 23,
     EXT_SESSION_TICKET => 35,
-    EXT_KEY_SHARE => 40,
+    EXT_KEY_SHARE => 51,
     EXT_PSK => 41,
     EXT_SUPPORTED_VERSIONS => 43,
     EXT_COOKIE => 44,