The U.S. House voted Wednesday afternoon to pass a major education bill that includes a ban on funding for any sex education programs that “normalize teen sexual activity as an expected behavior.”

The Student Success Act (HR 5) is a Republican rewrite of No Child Left Behind, a controversial education initiative that was one of President George W. Bush’s key policy priorities.

Debate over the rewrite has focused mainly on issues like the overuse of standardized testing, Common Core, teacher evaluations, and the role of federal and state governments in education.

But tucked away in the more than 600-page bill is language that seems intended to strip funding for evidence-based sex education in schools.

The bill prohibits funding for programs or materials “directed at youth, that are designed to promote or encourage sexual activity, or normalize teen sexual activity as an expected behavior, implicitly or explicitly, whether homosexual or heterosexual.”

Funds also cannot be used to help distribute materials on school grounds that are either “legally obscene” or, again, that “normalize teen sexual activity as an expected behavior.”

The bill also prohibits funding for contraceptive distribution in schools, or for sex education or HIV-prevention education programs that don’t teach “the health benefits of abstinence.”

The problem with this approach, advocates say, is that sex education is most effective when it acknowledges how normal teen sexual behavior actually is. Sixty-one percent of young people have already had sex by the time they turn 18, and 95 percent of Americans have sex before marriage.

A report by Advocates for Youth, an organization promoting adolescent sexual health, finds that effective sex education “should treat sexual development as a normal, natural part of human development” in order to help young people make healthy decisions about not just sex, but also relationships and bodily autonomy.

“Our young people deserve medically accurate and age-appropriate sex education so they can live healthy lives and have healthy relationships,” Rep. Barbara Lee (D-CA) told Rewire. “Sadly, this bill goes in the exact opposite direction by prohibiting funding for proven health and sex education curriculum that keep young people healthy.”

Lee has introduced another bill, the REAL Education for Healthy Youth Act, that would promote comprehensive sex education for young people.

“These restrictions, prohibiting sex education programs or materials that even acknowledge that young people engage in sexual activity, are a recipe for disaster,” Lara Kaufmann, director of education policy for at-risk students at the National Women’s Law Center, told Rewire. “This is just one of many things in HR 5 that would take education in this country in the wrong direction.”

Abstinence-only education programs, which often use shame and scare tactics to urge teenagers not to have any sex before marriage, have been repeatedly proven ineffective by researchers. Such programs have failed to reduce the number of teens having unprotected sex, and they are even correlated with higher teen birth rates.

Yet the federal government continues to fund abstinence-only programs, at a total cost of $1.7 billion since 1982, and Congress passed a first-ever funding increase for abstinence-only education earlier this year.

Republicans also proposed spending bills last month that would cut evidence-based teen pregnancy prevention programs by 80 percent.