diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 362117f..2408fd1 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1185,6 +1185,7 @@
 int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
 
 int mbedtls_ssl_tls13_process_finished_message( mbedtls_ssl_context *ssl );
+int mbedtls_ssl_tls13_write_finished_message( mbedtls_ssl_context *ssl );
 
 int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );