Change brackets type of references to numbered equations

The default bracket type around references to numbered equations is the standard parenthesis, e.g. (13). How can I change this setting such that the references appear as [13] with square brackets instead?
FWIW, I use LibreOffice Writer 5.2.


Autotexts in the Standard category may not be editable. The easiest way would be to insert a formula in a new document, modify the brackets, then select the table and create a new autotext in the “My Autotexts” category.