diff --git a/programs/x509/cert_app.c b/programs/x509/cert_app.c
index 2bac2ae..9459b2d 100644
--- a/programs/x509/cert_app.c
+++ b/programs/x509/cert_app.c
@@ -421,7 +421,7 @@
 
         mbedtls_ssl_set_rng( &ssl, mbedtls_ctr_drbg_random, &ctr_drbg );
         mbedtls_ssl_set_dbg( &conf, my_debug, stdout );
-        mbedtls_ssl_set_bio_timeout( &ssl, &server_fd, mbedtls_net_send, mbedtls_net_recv, NULL, 0 );
+        mbedtls_ssl_set_bio_timeout( &ssl, &server_fd, mbedtls_net_send, mbedtls_net_recv, NULL );
 
         if( ( ret = mbedtls_ssl_set_own_cert( &ssl, &clicert, &pkey ) ) != 0 )
         {