Only slightly more than half of tech pros surveyed by Dice are happy with their current salary.

Some 53 percent of respondents to the Dice Salary Survey said they were satisfied with their pay in 2015, a slight rise from 52 percent in 2014. That number represents a small but noticeable decline from 2012, when 57 percent expressed satisfaction.

Some 67 percent of tech pros also expressed confidence that they could find a new job in 2016.

For employers, such data can be taken as a warning sign that salaries—even historically high ones—aren’t necessarily enough to hold top talent in place.

In addition to increased compensation, employers resort to a variety of perks to keep their best and brightest, including flexible work locations, more interesting (or challenging) work, adjustable schedules, promotions or bonuses, and free training.

But if you look at Dice’s data, the number of companies actually using those alternate perks is relatively small; for example, only 9 percent offered flexible work hours.

And therein lies the lesson for employers: offering more perks is a good way to keep employees onboard. For tech pros, the takeaway is likewise clear: try negotiating for perks, and it’s likely that your employer—all too aware of the incredible demand for tech talent—will listen to your request.