Forgot to enter 1099-R which was a QCD

I forgot to enter a 1099-R on my 1040.  The entire amount was my RMD from a traditional IRA and was distributed directly to qualified charities.  I've gone through the steps of completing an amended return but since the amount is considered a Qualified Charitable Distribution (QCD) there is no change to my taxable income or any other values on 1040-X.  How do I notify the IRS of the omission and the fact that it's a QCD?