diff --git a/lib/auth_cert.c b/lib/auth_cert.c
index 54b4a50..a25b753 100644
--- a/lib/auth_cert.c
+++ b/lib/auth_cert.c
@@ -869,7 +869,10 @@ _gnutls_proc_x509_server_certificate (gnutls_session_t session,
   size = _gnutls_read_uint24 (p);
   p += 3;
 
-  if (size == 0)
+  /* some implementations send 00 00 03 00 00 00
+   * instead of just 00 00 00.
+   */
+  if (size == 0 || size == 3)
     {
       gnutls_assert ();
       /* no certificate was sent */