How to suppress Simulink Extract Bits overflow warning?

Extract bits from a fixed point, I always get Overflow warning regardless how 'Output scaling mode' is set.

I won't need real-world value propagate through the 'Extract bits' block, how to suppress the warning or how to use the block properly without generating such warning.

I've noticed the way of having a fcn call of bitsliceget() will not generate such warning. But are there alternative way of doing this?

Thanks,

[Si Cheng]

The same problem, even have already set input datatype as uint8.