Is there a way to validate JSF readonly fields?

I'm working on a JSF project using PrimeFaces and I have some custom components to facilitate the work. One them is a search component that is formed for a input text with a button that open a dialog. In the dialog I have a data table that lists some data. When the user chooses some record, the input text is updated with this record and the the managedbean is updated too. To avoid curious users, that could change the value of the input text, I set a readonly in this field, but the field is required. Here is the problem, the JSP doesn't validate readonly fields, and my validation rules are broken.

Is there a way to validate readonly fields when I submit the form?

Thanks.