diff --git a/oop-www.h b/oop-www.h
index fc4f5019f596d02940ee34b94fc9ff5536a39b4c..86e0d1d70c69851e2d3a5332d2096691d053cef9 100644
--- a/oop-www.h
+++ b/oop-www.h
@@ -19,10 +19,10 @@ void oop_www_register(oop_source *);
 
 /* Release any resources associated with the event manager, and
    unregister it with libwww.  This will leave libwww with no event manager. */
-void oop_www_cancel();
+void oop_www_cancel(void);
 
 /* Use libwww's memory management for liboop.
    ** If you use this, you must do so before any other liboop function! ** */
-void oop_www_memory();
+void oop_www_memory(void);
 
 #endif