1 files changed, 1 insertions, 1 deletions
diff --git a/ioport.c b/ioport.c
index ef6fb96c63..3a6a73dd98 100644
--- a/ioport.c
+++ b/ioport.c
@@ -211,7 +211,7 @@ static void portio_list_add_1(PortioList *piolist,
      * Use an alias so that the callback is called with an absolute address,
      * rather than an offset relative to to start + off_low.
      */
-    memory_region_init_io(&mrpio->mr, &portio_ops, mrpio, piolist->name,
+    memory_region_init_io(&mrpio->mr, NULL, &portio_ops, mrpio, piolist->name,
                           off_high - off_low);
     memory_region_add_subregion(piolist->address_space,
                                 start + off_low, &mrpio->mr);