diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index e4374185b9..43067cfb19 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -990,6 +990,7 @@ static ssize_t tun_write(FAR struct file *filep, FAR const char *buffer,
       if (priv->write_d_len == 0)
         {
           net_lock();
+          netdev_iob_release(&priv->dev);
           ret = netdev_iob_prepare(&priv->dev, false, 0);
           priv->dev.d_buf = NULL;
           if (ret < 0)