How do I clear error on Box 6 on my 1099-DIV?

My "foreign taxes paid" is $20, which also appears on line 48 of my 1040. Since this is passive, per IRS doc, I don't think I need to fill out form F1116.  TT says I need to enter something in 1099-DIV box 6d.  I think I understood someone's post to say I could just enter a 0.00 in 6d, but I wanted confirmation.  It looks like I need to do SOMETHING to clear the error.  Just to see what would happen, I clicked the box for 6a, and it reduced my refund by $30...which is more than the amount I already paid!  Please advise.