diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 009b43f6d045e273ae28d47d66440536a257d1a5..e7ea0e45f3ddbe661ab409102e19bd9c779888a4 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -57,12 +57,12 @@ static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
         }
 
         BUG_ON(elem->out_num == 0 || elem->in_num == 0);
-        QEMU_BUILD_BUG_ON(sizeof out != 7);
+        QEMU_BUILD_BUG_ON(sizeof(out) != 7);
 
         v->elems[pdu->idx] = elem;
         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
-                         &out, sizeof out);
-        BUG_ON(len != sizeof out);
+                         &out, sizeof(out));
+        BUG_ON(len != sizeof(out));
 
         pdu->size = le32_to_cpu(out.size_le);