diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index bc8b161..fa6c4c6 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1174,7 +1174,9 @@
     if (mbedtls_ssl_conf_tls13_some_psk_enabled(ssl) &&
         ssl_tls13_early_data_has_valid_ticket(ssl) &&
         ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_ENABLED) {
-        ret = mbedtls_ssl_tls13_write_early_data_ext(ssl, p, end, &ext_len);
+
+        ret = mbedtls_ssl_tls13_write_early_data_ext(
+            ssl, p, end, &ext_len, NULL);
         if (ret != 0) {
             return ret;
         }