Index: uspace/lib/hound/include/hound/server.h
===================================================================
--- uspace/lib/hound/include/hound/server.h	(revision 984a9ba2fa05c490a7066737655ed19130c714e8)
+++ uspace/lib/hound/include/hound/server.h	(revision d054ad327ffe0b12fea2dcc17f0711048959b7b2)
@@ -40,10 +40,11 @@
 #include <loc.h>
 
-typedef void (*dev_change_callback_t)(void);
+typedef void (*dev_change_callback_t)(void *);
 typedef errno_t (*device_callback_t)(service_id_t, const char *);
 
 errno_t hound_server_register(const char *name, service_id_t *id);
 void hound_server_unregister(service_id_t id);
-errno_t hound_server_set_device_change_callback(dev_change_callback_t cb);
+errno_t hound_server_set_device_change_callback(dev_change_callback_t cb,
+    void *);
 errno_t hound_server_devices_iterate(device_callback_t callback);