Gov. Jerry Brown has approved legislation aimed at making California the first state in the nation to bring lessons about sexual consent required at many colleges into high schools, his office announced Thursday.

Last year, California became the first to require colleges and universities to apply an "affirmative consent" or "yes means yes" standard when investigating campus sexual assault claims. That policy says sexual activity is only considered consensual when both partners clearly state their willingness to participate through "affirmative, conscious and voluntary agreement" at every stage.

The legislation Brown endorsed requires school districts that already include health as a graduation requirement to teach about "yes means yes" and sexual violence prevention starting next year. It also asks state education officials to update curriculum guidelines for high school health classes with information about those topics.

"California must continue to lead the nation in educating our young people — both women and men — about the importance of respect and maintaining healthy peer and dating relationships," Assemblyman Rocky Chávez, R-Oceanside, said after the bill cleared the Assembly in September.

The measure had no organized opposition and received near-unanimous bipartisan support in the Legislature. Supporters said it was needed to teach teenagers about healthy sexual boundaries and relationships before they get to college and into the workforce.

In July, New York became the second state to write the affirmative consent standard into law for college campuses. But it's becoming the norm at colleges around the country that are under the same pressure to reduce and better handle sexual assault cases.

Although the new law for high schools will take effect on Jan. 1, its immediate effect will be mostly emblematic. The California Department of Education commission that develops curriculum standards is not scheduled to revise health education guidelines until 2018, and then only if provided funding for the work.

As a result of previous legislation, that commission also has been asked to update health standards with learning goals related to mental health, abusive relationships and preventing sex trafficking.

The affirmative-consent law Brown just signed only applies to school districts that require a health course as a condition for receiving a high school diploma. The state Legislative Analyst's Office said five of the state's largest school districts, including Los Angeles Unified, have such a requirement.

Brown also signed legislation requiring all school districts to provide comprehensive sex education classes twice between grades 7 and 12. Currently, sex education is not mandatory, although the vast majority of school districts provide it.

The measure, AB 329, by Assemblywoman Shirley Weber, D-San Diego, also updates the instruction provided in schools on HIV prevention, makes clear that sex education must address students of all sexual orientations and adds new language relating to teen relationship abuse and sex trafficking.

Parents would still be allowed to excuse their child from some, or all, of the sex education curriculum.

A 2011 report from the University of California, San Francisco, found problems with school districts' compliance with the current law on sex education. Among its findings, only a quarter offered the required information about emergency contraception and a quarter omitted required HIV-prevention topics.