diff --git a/src/vnet/devices/virtio/virtio.c b/src/vnet/devices/virtio/virtio.c
index 72499b6..9fbbc1b 100644
--- a/src/vnet/devices/virtio/virtio.c
+++ b/src/vnet/devices/virtio/virtio.c
@@ -121,7 +121,7 @@
       do
 	{
 	  if (n_alloc < sz)
-	    n_alloc =
+	    n_alloc +=
 	      vlib_buffer_alloc (vm, vring->indirect_buffers + n_alloc,
 				 sz - n_alloc);
 	}