Index: kernel/generic/include/ipc/event.h
===================================================================
--- kernel/generic/include/ipc/event.h	(revision 0d8a304c1941d4b637abf937d8947384c88d0e1c)
+++ kernel/generic/include/ipc/event.h	(revision 97d42d5e11dcee14940db22d71b410bb48103e65)
@@ -41,4 +41,6 @@
 #include <ipc/ipc.h>
 
+typedef void (*event_callback_t)(void);
+
 /** Event notification structure. */
 typedef struct {
@@ -51,13 +53,14 @@
 	/** Counter. */
 	size_t counter;
+	
 	/** Masked flag. */
 	bool masked;
 	/** Unmask callback. */
-	void (*unmask_cb)(void);
+	event_callback_t unmask_callback;
 } event_t;
 
 extern void event_init(void);
 extern void event_cleanup_answerbox(answerbox_t *);
-extern void event_set_unmask_callback(event_type_t, void (*)(void));
+extern void event_set_unmask_callback(event_type_t, event_callback_t);
 
 #define event_notify_0(e, m) \