David Manning / Reuters

A San Francisco-area Boy Scout says he has been denied the organization’s most prestigious award because he is gay, Yahoo News reports.

Seventeen-year-old Ryan Andresen’s troop leader informed him that despite completing the requirements to be an Eagle Scout, he could not earn the honor because of his sexual orientation, Andresen’s mother told Yahoo. Andresen said his troop leader was aware of his orientation before he began applying for the rank.

“He had been telling me all along that we’d get by the gay thing,” Andresen told Yahoo. “It was by far the biggest goal of my life. It’s totally devastating.”

Andresen joined the Boy Scouts when he was six years old, but on Monday he will turn 18—the cut-off age for receiving the Eagle Scout award.

In order to earn the distinction, scouts must reach five ranks, obtain 21 merit badges, maintain a leadership position for six months and complete a service project. For his project, Andresen worked with students to construct an anti-bullying “Tolerance Wall” at his local middle school, which comprises 288 ceramic tiles depicting acts of kindness, Yahoo notes.

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Andresen’s mother launched a petition on Change.org to convince her son’s scoutmaster to change his decision before Andresen’s birthday. The petition has over 150,000 signatures as of Friday afternoon.

“It hurts me so much to watch Ryan suffer for being who he is, because to me, he’s perfect,” she wrote on the website. “Ryan has worked for nearly 12 years to become an Eagle Scout, and nothing would make him more proud than earning that well-deserved distinction.”

Deron Smith, the national spokesman for the Boy Scouts, said on Thursday that Andresen does not abide by the organization’s religious principles.

“Recently, a Scout proactively notified his unit leadership and Eagle Scout Counselor that he does not agree to Scouting’s principle of ‘Duty to God’ and does not meet Scouting’s membership standard on sexual orientation,” Smith wrote in a statement to Yahoo News. “While the BSA did not proactively ask for this information, based on his statements and after discussion with his family he is being informed that he is no longer eligible for membership in Scouting.”

In July, a committee of BSA leaders concluded unanimously that the organization would continue its policy of excluding homosexuals. The policy was upheld by the Supreme Court in 2000, but many companies have cancelled donations in protest.

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Andresen came out to his troop in a letter he wrote in July to address a bullying incident because he “thought he could help,” his mother told ABC News. Andresen himself had been bullied, and after he left the Boy Scouts for a few months because of the vicious teasing, his scoutmaster, Rainer Del Valle, encouraged him to return and complete his service project. Now, however, Del Valle will not provide the final signature for Andresen’s award, ABC News reports.