In late 2015, Jennifer Panattoni, a police officer in the Chicago suburb of Frankfort, Illinois, got an early Christmas gift: She and her husband, a fellow officer, learned they were expecting their first child. After enduring nearly two years of fertility treatments, Panattoni—a 13-year veteran of the force—was elated to finally be pregnant.

But it soon became clear that the Frankfort Police Department leadership did not share her joy. Although Panattoni—one of just three women on the force of about 30 members—initially was able to continue working full-duty as a patrol officer, she knew that eventually she would need to curtail her time on the street. So she asked the chief of police about arranging for a temporary reassignment to something safer, like a desk job. The answer was a resounding no, according to Panattoni.

Why? Because he claimed the department had a policy of awarding such positions only to officers injured on the job. As the chief told Panattoni, “I only have to treat you like someone who broke a leg” during off-duty hours. Adding insult to injury, she said the department also refused her request for a bulletproof vest, maternity uniform, and shoulder holster—instead of the standard-issue, 25-pound duty belt—to accommodate her changing body. Eventually, it scrounged up an ill-fitting men’s shirt and pants.

Panattoni continued patrolling the streets until she was nearly five months pregnant, when her doctor directed her to switch to less hazardous duties. But the department still refused to accommodate Panattoni in any way, she explained. Instead, it sent her home for the remainder of her pregnancy. Panattoni ran out of paid sick and personal days just one month after being forced off the job. So for the three months until she gave birth and through her two-month maternity leave, she got by on disability payments—which amounted to only a fraction of her paycheck.

This isn’t the way it’s supposed to be. Thirty-eight years ago today, Congress enacted the Pregnancy Discrimination Act (PDA) of 1978, which declared pregnancy discrimination to be a form of sex discrimination. The PDA also directs that pregnant workers are to receive the same benefits—like temporary light duty work—that their nonpregnant colleagues do.

The Supreme Court reiterated this standard last year when it decided Young v. United Parcel Service, Inc., a case involving another pregnant woman who needed a temporary reprieve from her job duties, which occasionally required heavy lifting. If an employer excludes pregnant women from a policy that grants accommodations to nonpregnant workers—such as workers hurt on the job—it must have a good reason for doing so. Otherwise, said the Court, it must grant pregnant employees the same opportunity to continue earning until it’s time for them to give birth.

Yet cases like Panattoni’s remain distressingly common. Between 1997 and 2011, the number of pregnancy discrimination charges filed with the U.S. Equal Employment Opportunity Commission (EEOC) increased by almost 50 percent. The bulk of those claims are filed by women who, like Officer Panattoni, work in male-dominated fields that often are hazardous and women in low-wage fields, where jobs may require prolonged standing and other physical strain. The companies are on the receiving end of these charges are household names, such as Procter & Gamble, Walmart, Macy’s, and Chipotle.

One study showed that as many as a quarter million pregnant women a year don’t get the accommodations they need to be able to safely continue working. That means women lose wages or even their jobs—as is the case for women who lack access to job-protected leave programs—just when they’re needed most. Given that 85 percent of working women will become pregnant at least once in their careers, and that women now are the primary breadwinners in roughly half of U.S. households, it doesn’t take an expert economist to understand that pregnancy discrimination isn’t just a civil rights issue, it’s a financial one—for families and for all of us.

Recognizing this fact, 18 states—including Illinois—have taken additional steps to protect pregnant workers by enacting laws that expressly require employers to offer reasonable accommodations to pregnant workers. And in 2012, the International Association of Chiefs of Police issued a model maternity policy that recommended light duty automatically be available to pregnant officers so that they could keep serving, and earning, until their due dates. Even the federal government is taking notice: Last week, the U.S. Department announced the settlement of its suit against a Kentucky police department for failing to provide light duty to two pregnant officers; the officers will receive monetary damages, and the department will implement a new pregnancy accommodation policy.

As Panattoni’s case suggests though, some employers still aren’t getting the message. That’s why we are representing her in her charge of discrimination filed with the EEOC, the first step toward filing a federal lawsuit.

Such legal action is an unfortunate, but necessary, way to ensure that bosses treat pregnancy like the common medical event that it is. Nearly four decades after Congress mandated that working women not be penalized for being pregnant, it’s beyond time to make the law mean what it says.