A 16-year-old boy brought an antique pistol into his Queens high school Tuesday and was promptly busted, police said.

Police showed up to Grover Cleveland HS on Himrod Street in Ridgewood after the student tried to walk through a metal detector with the inoperable weapon around 7:50 a.m.

The boy told cops he did not intend to harm anyone and accidentally entered the building with the gun after forgetting to remove it from his bag.

He had apparently been using the gun as part of a photography project outside of school, officials said.

It is not immediately clear if the boy will face charges.

The incident comes as city schools face a 48 percent increase in weapon seizures this year as of Sept. 30, with 328 having been recovered so far compared with 222 for the same period in 2016.