I wouldn't lie with a specific number, but I would answer it with either one of these two options:

1. You're probably more aware of the market conditions than I am and I trust you to make me a competitive offer should we both agree this is a good match

2. I have an embarrassingly high compensation in my current role, and I am not comfortable in divulging it, because very few employers are able to match it and I'm not expecting them to

Both answers put the onus on the employer to put out their best offer possible, and any push back is basically a huge red flag.