diff -up ./gtk/spice-session.c.orig ./gtk/spice-session.c
--- ./gtk/spice-session.c.orig	2011-12-20 20:07:16.113945269 +0000
+++ ./gtk/spice-session.c	2011-12-20 20:08:19.910053425 +0000
@@ -1402,7 +1402,7 @@ GSocket* spice_session_channel_open_host
         g_clear_error(&conn_error);
         sock = channel_connect_socket(sockaddr, &conn_error);
         if (conn_error != NULL)
-            g_warning(conn_error->message);
+            g_warning("%s", conn_error->message);
         g_object_unref(sockaddr);
     }
     g_object_unref(enumerator);