extern const uschar *process_purpose; /* for debug output */
extern BOOL prod_requires_admin; /* TRUE if prodding requires admin */
-#if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
+#if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS) || defined(EXPERIMENTAL_XCLIENT)
extern uschar *hosts_proxy; /* Hostlist which (require) use proxy protocol */
extern uschar *proxy_external_address; /* IP of remote interface of proxy */
extern int proxy_external_port; /* Port on remote interface of proxy */