A New Zealand private school is changing its dress code to explicitly allow hijabs in the wake of the mass shooting at two mosques in Christchurch that left 50 people dead.

The Diocesan School for Girls in Auckland announced the change on Facebook on Friday.

"Diocesan School advises that it is clarifying its intent by revising its school uniform policy so that any student who wishes to wear the hijab can do so," the principal, Heather McRae, said in the Facebook post.

The policy change came after the school initially announced that students could wear hijabs for a "scarves in solidarity" event Friday in remembrance of the March 15 shooting by a suspected white supremacist.

That sparked a flurry of pushback, mostly by alumni, against any restrictions on the Muslim head covering.

The principal at first wrote in a now-deleted Facebook post that the school dress code was created to "help create a sense of oneness and family" and that while the hijab isn't "banned," it is also "not part of the long-standing Uniform Code."

Qiulae Wong, 30, who graduated from the private school in 2006, said this initial announcement made it clear that the headscarf was prohibited on other days.

"We were privileged to go to a school like Diocesan — but we recognize that with privilege comes an even greater responsibility to the wider community," Wong and a group of Diocesan School for Girls alumni said in a statement to NBC News.

They decided to write an open letter to the school in a Change.org petition that states a policy against hijabs does not "represent our views and what we think the school should be doing." The petition had more than 850 signatures as of Friday, and Wong says the majority are former students of the school.

"We were deeply disappointed to read your statement regarding the uniform policy at Dio in the wake of the terrorist attack in Christchurch — both for its content and its timing," the former students wrote.

Then on Friday, the principal announced the change in policy. She said there has never been any formal request from any student or parent to wear the hijab, but it is now "an appropriate time to revise" the policy to allow it.

Wong said expressions of support for the Muslim community in New Zealand after the attacks has been "overwhelming." This decision by her former school is "about more than hijabs, but about recognizing all of society's injustices and the role we can play in correcting them."