diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index ec0df65f90..3730483d8a 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1384,6 +1384,8 @@ static int ssl_tls13_write_hello_retry_request_coordinate(
     if( ssl->handshake->hello_retry_request_count > 0 )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "Too many HRRs" ) );
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+                                      MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
         return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
     }