How do I go about talking to my landlord about entering without asking/knocking?

My landlord has entered my apartment a couple times without asking me or even knocking, despite the clause in my apartment that he wouldn’t do that except in an emergency. Today’s was definitely not an emergency, and definitely not so urgent that he couldn’t knock, allowing me to make sure I was clothed, not in a compromising position, didn’t have dirty underwear out, etc. How do I politely but firmly ask him to cut it the hell out?