How do I stop hardwood floors which are installed on concrete slab from making noise/squeaking?

When I search the internet for this question, all I get back are answers for a wooden sub-floor. What If I'm on a slab? Wood is very old and very beautiful. Pulling it up is not an option. The large squeaky areas are near a water source, so I'm assuming a small amount of water intrusion in the past has failed whatever adhesive was used to keep it down. Also, when I knock on the squeaky area, it seems a slightly bit hollow sounding like the wood is not affixed properly. Also finish is gloss so I can't put talc between the boards.