Source paramater for aspnetForm not working in SharePoint 2013

With SharePoint 2010 I could do something like this to redirect the new form back to the new form on save.

document.getElementById("aspnetForm").action = "/path/to/NewForm.aspx?Source=/path/to/NewForm.aspx"

However, this does not seem to work in SharePoint 2013 anymore.

I basically need the new form to keep redirecting back to itself. I know I can create a link like this for it to redirect but it will only work the first time because the Source parameter is not set after that.

<a href="/path/to/NewForm.aspx?Source=/path/to/NewForm.aspx">New Item</a>