diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index aec01420d979..527dc2a3b89f 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -105,7 +105,7 @@ struct xenbus_file_priv {
 	unsigned int len;
 	union {
 		struct xsd_sockmsg msg;
-		char buffer[PAGE_SIZE];
+		char buffer[XENSTORE_PAYLOAD_MAX];
 	} u;
 
 	/* Response queue. */