Having spent decades in tech, I have numerous memories of being the only woman in the room. To be taken seriously, I had to possess a lot of confidence and be certain of myself—particularly as I rose up the leadership chain. Being confident may sound simple, but actually it’s not. In The Confidence Code, Katty Kay and Claire Shipman found that women tend to focus more on developing competence instead.

I’ve coached many women who think this way: They come into our first meeting firm in the belief that if they just work harder and hone their expertise, they will automatically be recognized and rewarded for it. Of course, excellence is important and shouldn’t be overlooked. But the world often places a higher value on confidence. It’s not just what you know, but how good you are at standing firm in that knowledge.

For women, this can be a challenge. We’re not as good as men are at projecting certainty. We tend to downplay it, which makes matters worse. It’s not that we’re less knowledgeable, but downplaying certainty is a useful behavior in a relationship-focused communication style, built on establishing and maintaining intimacy. The problem is that it doesn’t make someone look confident. It also doesn’t address the behaviors you often see in the workplace, in which men tend to downplay their doubts and overstate their opinions.

It’s not that men intend to mislead others by not expressing their doubts. They may actually believe they are right. This approach comes in handy in an innately status-conscious world, but it has its own disadvantages. It can lead to a competition between conflicting and overinflated opinions, and an unfortunate habit of treating those who don’t understand the argument as if they are directly disagreeing.

In public, men state seemingly outrageous thoughts and ideas in order to test them out. As Deborah Tannen explains, they actually expect others to shoot these ridiculous notions down. But if no one does, they may continue to push to the point of unreasonableness.

If you’re the only woman in the room, it’s important to recognize when this is happening. A woman engineer at a tech company recently asked me what to do when a man hijacks a meeting with absurd ideas. Another woman we were with spoke up: “I tell them their idea is ridiculous, and to back it up with facts. Then I steer the conversation toward a more productive, inclusive outcome.”

If you find yourself in such a situation, but are feeling insecure, it can be difficult to act confidently. One way to find courage is to utilize confident body language. Leaning back in your chair and taking up space in the room display a sense of self-assuredness. Speaking with authority in a calm voice is another sign. I often help women develop a mental touchstone—something they can turn to in a moment of doubt. My own is thinking of riding a spooked horse: The same behaviors that calm a horse also convey confidence to a room filled with men. When I sense my confidence dip for a moment, I imagine settling down that horse.

Being confident is part of how we give ourselves power, another key to being taken seriously. As women, we often have an ambiguous relationship with the notion of being powerful. It may be that our skill at forming personal relationships makes us uncomfortable with moving out of a position of equality to assume one of power. But that’s what we need to do if we want to succeed in the business world.

The next time you’re in a room filled with men, don’t worry about having a fully formed idea before speaking. Just speak up—and with force. Having a passionate voice is more important than having no voice at all. Harness that passion confidently in your body language and speech. Take up space, embrace your confidence, keep calm, and lead.