Index: uspace/srv/hid/compositor/compositor.c
===================================================================
--- uspace/srv/hid/compositor/compositor.c	(revision 984a9ba2fa05c490a7066737655ed19130c714e8)
+++ uspace/srv/hid/compositor/compositor.c	(revision 6abff2a8b48b577b0150c419532e65aeff614f3b)
@@ -2262,5 +2262,5 @@
 }
 
-static void category_change_cb(void)
+static void category_change_cb(void *arg)
 {
 	discover_viewports();
@@ -2311,5 +2311,5 @@
 	}
 
-	rc = loc_register_cat_change_cb(category_change_cb);
+	rc = loc_register_cat_change_cb(category_change_cb, NULL);
 	if (rc != EOK) {
 		printf("%s: Failed to register category change callback\n", NAME);