diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 6995f47..53a01cf 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1008,7 +1008,7 @@
 {
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
     if (ssl->handshake->resume) {
-        if (mbedtls_ssl_session_check_ticket_flags(
+        if (!mbedtls_ssl_session_ticket_has_flags(
                 ssl->session_negotiate, kex_mode)) {
             return 0;
         }