Non Jew working on Shabbat

Hi,

I have a contractor scheduled to build a fence around my yard next Friday. Due to high demand, he had no other availability. The work is not expected to take more than a day and he is supposed to start in the morning. Is there any issue if he continues to work past candle lighting time or for some reason needs to extend the job until Saturday if no money will be exchanged during Shabbat?

The issue is Maaras Ayin and therefore not allowed. Ask him to stop and continue after Shabbat.