Does an elective 401k deferral reduce earned income for Dependent care Credit?

I have an earned income well in excess of any minimums, but my wife through our S-Corp had wages of 8k. The full 8k was subject to Social Security and Medicare, but she electively deferred 6k to a 401k so box 1 only shows 2k.

For the purposed of qualifying for dependent care tax credit would the wages utilized be the 8k that she paid social security medicare or the less post 401k 2k?