diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 7508685..e130fa5 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -688,6 +688,19 @@
         p += extension_data_len;
     }
 
+    /*
+     * Server certification selection (after processing TLS extensions)
+     */
+    if( ssl->conf->f_cert_cb && ( ret = ssl->conf->f_cert_cb( ssl ) ) != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "f_cert_cb", ret );
+        return( ret );
+    }
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+    ssl->handshake->sni_name = NULL;
+    ssl->handshake->sni_name_len = 0;
+#endif
+
     /* Update checksum with either
      * - The entire content of the CH message, if no PSK extension is present
      * - The content up to but excluding the PSK extension, if present.