diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 736cd208e4..41d2a321ec 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -184,6 +184,8 @@ static int ssl_tls13_write_client_hello_ciphersuites(
                            ( "client hello, got %" MBEDTLS_PRINTF_SIZET " ciphersuites",
                              buf_len/2 ) );
 
+    *olen = ciphersuite_iter - buf;
+
     return( 0 );
 }