How to sync if model id is hidden field?

I'm trying to sync data to pivot table for my model. But my Recipe model has an hidden id field. Like this;

protected $hidden = ['id', 'content', 'difficulty_id'];

And when I try to sync relationships to pivot table, recipe_id becomes zero. If I remove id from $hidden above, it sync id without any problem. I also tried to call makeVisible("id") for the model but didn't help.

$changedMeals = $record->meals()->sync($meals);

How can I sync id when keeping it in $hidden?

Thank you very much...

via Chebli Mohamed