If my years of marketing experience have taught me anything, it’s this: The brand that will make or break your career isn’t the one you work for—it’s the one you build for yourself. Your personal brand can work hard for you or it can weigh you down.

Of course, in an age of selfie sticks and hashtags, it’s tempting to dismiss the idea of personal brand as a marketing gimmick. But your personal brand is about more than self-promotion and “likes” on social media: It’s your currency in the workplace.

People with positive personal brands get the most interesting assignments, more credit, and the opportunity to work with top talent. People with negative personal brands get typecast and passed over for promotion. Your personal brand also influences the way your colleagues perceive the work you do—and reflects on your department or team. It determines whether people want to work with you and how they share and receive information with you.

And as with any consumer brand, you’re lucky if people remember three defining characteristics about you. Think of a colleague you interact with on a semi-regular basis. What three words would you use to describe them? You’re probably stretching for the third, right? If the sum total of what you’re known for gets boiled down to three attributes, you owe it to yourself to think hard about what you want them to be and take deliberate action to reinforce them.

Here’s how you can start defining your personal brand before it defines you:

Authenticity
You can only be known for something if it’s actually true to who you are. Yet I often see people get tripped up because they want to be recognized for something they’re not particularly adept at. A while back, I mentored someone who thought he needed to be an expert on financials because he was surrounded by folks who were. But he was a marketer. After some coaching, he realized he needed to have enough knowledge in financials to be dangerous, but an expert in the areas he was already good at, like customer insights and creative strategy. It’s important to work with what you’ve got and lean into your strengths.

Differentiation
When you’re part of an established corporate culture, it’s common for employees to share a number of impressive attributes. At many companies, being “smart” isn’t a differentiator—it’s the expectation. While you should live up to those standards, don’t waste time trying to distinguish yourself on qualities that everybody has. Focus on what sets you apart, whether it’s your calm demeanor or a knack for working across teams to get things done.

Adaptability
Your personal brand should evolve whenever you change roles, teams or companies. The qualities I was most known for at Microsoft (MSFT), like retail channel expertise and consumer tech knowledge, weren’t going to help me much at Capital One (COF), so I focused on different strengths. And in my new role at Uber, I’m intentionally shifting my personal brand once again. Be self-aware about what you bring to a new team, and be prepared to exercise different strengths when circumstances around you change.

Bravery
There are some negative traits that no amount of polish can overcome. If you have a reputation for dishonesty or stealing credit, you should work on those issues first. I recommend a direct conversation with the people who hold this belief most strongly (be brave!). Acknowledge your wrongdoing in the past and ask them to help track your progress. People respect vulnerability and will want to be part of your transformation.

There’s no way to change your brand overnight, but every interaction you have is an opportunity to polish (or tarnish) your reputation. So seize the day. In my line of work, I know how much effort it takes to manage a successful brand. Believe me. Your patience and persistence will pay off in the end.