Son asked if it was his fault we split up - how did you handle this?

My 7yo asked yesterday if Mommy and Daddy got divorced because of something he did. Absolutely gutted me. I told him it was 100% an adult thing, nothing to do with him, we both love him, etc. He seemed to accept it but I'm wondering if I handled it right or if there's something else I should have said?

Never dealt with this before and I don't want to screw it up.