Yes, this is what you should do as this man is not father.

I am a Male. My mother is a Muslim and my father is a Christian and he never was a Muslim. My mother and father were not married when they had me and they never got married after. I was raised a Muslim though. It is permissible for me to add an Islamic name to my last name such as AdurRahman or Abdullah?

Illegitimate children & Lost property |