diff --git a/common/rfb/Security.cxx b/common/rfb/Security.cxx
index e623ab5..4987b29 100644
--- a/common/rfb/Security.cxx
+++ b/common/rfb/Security.cxx
@@ -52,7 +52,7 @@ static LogWriter vlog("Security");
#ifdef HAVE_GNUTLS
StringParameter Security::GnuTLSPriority("GnuTLSPriority",
"GnuTLS priority string that controls the TLS session’s handshake algorithms",
- "NORMAL");
+ "@SYSTEM");
#endif
Security::Security()