diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index f14f372..467d594 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -77,6 +77,7 @@
  * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
  * and may be nested.
  */
+void synchronize_rcu(void);	/* Makes kernel-doc tools happy */
 synchronize_rcu_xxx(synchronize_rcu, call_rcu)
 EXPORT_SYMBOL_GPL(synchronize_rcu);