diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 73d78dc9b875c49b2abf3188f1ff7efac658f776..332dd63750a01d41342844bc3f72e25891c4eab4 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -529,7 +529,7 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
 
 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
 		/* Clear master flag /before/ clearing selector flag. */
-		rmb();
+		wmb();
 #endif
 		pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
 		while (pending_words != 0) {