Thank you for your comment, I was starting to wonder if I'm the only one to have stumbled on this.

The workaround proposed at stackoverflow works on postgresql, but breaks all other databases.
In my particular case I need to support 3 different databases and therefore hard-coding de column definition is not viable option.

So far, the only solution I've found have been "fixing" the postgresql scripts manually. As long as the database column is correct, everything else seems to work as intended.