diff --git a/include/sys/threads.h b/include/sys/threads.h
index cfb8ab9f..b9f9111f 100644
--- a/include/sys/threads.h
+++ b/include/sys/threads.h
@@ -74,7 +74,7 @@ static inline int beginthread(void (*start)(void *), unsigned int priority, void
 }
 
 
-extern int threadsinfo(int n, threadinfo_t *info);
+extern int threadsinfo(int tid, unsigned int flags, int n, threadinfo_t *info);
 
 
 extern int priority(int priority);