Can I fit a kitchen sink too tightly?

[MarkShezza]

First time I've fitted a sink (it's for me dear ol' mum) and I've put a 40mm thick Oak worktop in. Being ultra careful, I've got the aperture absolutely spot on, ie, the sink fits in the hole like a glove. My niggling concern is that any expansion might force the sink up and out in the future. It's also so snug that I can't even use the fitting clips to secure it; can I just chisel out a few slight indents to take a limited number of fixing clips? Or, would siliconing-it in be sufficient anyway?

 

[mysteryman]

If the wood expands with wetness, it may expand and crack the sink.