Gov. Phil Murphy signed a new law last month limiting the size of firearms magazines in New Jersey to 10 rounds as part of a package of bills meant to tighten the state's already strict gun laws.

But the measure, which made possession of larger magazines a crime, with a few exceptions, had unintended consequences for police officers in the Garden State.

Now lawmakers are looking to clean up the problem, and the state Senate is slated Thursday to vote on a bill that would clarify how the high-capacity magazine ban applies to law enforcement.

State Sen. Loretta Weinberg, D-Bergen, a sponsor of the measure, said it was meant to "correct an oversight" that may have prohibited some police officers from carrying their service weapons while off duty.

The law passed in June changed New Jersey's magazine limit from 15 rounds to 10 rounds, putting in place a 180-day "grace period" for gun owners to turn in large magazines that are now illegal.

While it carved out certain exceptions for retired law enforcement, Weinberg said her legislative office became aware of concerns over how the new law might affect active-duty officers.

Luis Bordi, the chief of police in Voorhees Township and a vice president at the New Jersey State Association of Chiefs of Police, told NJ Advance Media any officer possessing a weapon with a magazine larger than 10 rounds could be violating the current law in certain circumstances.

Most police service weapons use magazines containing between 12 and 17 rounds, he said, and police officers are never completely off the clock.

"They're required to act depending on what happens in front of them, and they need to be able to protect themselves and the community, even if they're off-duty," Bordi said.

The new measure, S-2846, "allows a law enforcement officer to possess and carry while off-duty a large capacity ammunition magazine capable of holding 17 rounds of ammunition or less," according to the text of the bill.

It also allows off-duty police to possess a larger magazine "provided it is used with the officer's service firearm issued by the officer's employer."

The law would effectively establish different rules for how much ammunition police and civilians can carry. It's unclear whether the existing law has affected any active-duty cops.

Gun rights advocates opposed the magazine limit signed by Murphy last month, saying it would not prevent gun violence and instead would turn law-abiding gun owners into criminals if they didn't surrender their now-illegal magazines on time.

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.