The move comes after a fire in Brooklyn in which a father and two children died this week raised questions on a new system which began in May. Fire union officials said the system caused a delay in getting to the fire. FDNY brass said it wasn't true.
Firefighters were initially sent to the wrong address in another deadly fire two weeks ago.
Rescue crews raced to 62nd Street in Woodside, Queens when the fire was actually burning at a home on 65th Street.
Three people living in an illegally subdivided apartment died in that blaze, and firefighters on the scene speculated they would have been able to save at least one of the men if they'd gone directly to the right house.
The 911 systems used to be separate for police and fire calls, but the new system combines them, and sends emergency fire information taken by police operators directly to FDNY dispatchers. The controversial unified call taking system is designed to save time by having just one person asking the caller questions, but some critics charge the system is vulnerable to mistakes.
City officials say there is proof that the system is working: since it was introduced, response times are down 16 seconds, to under 4 minutes.
Fire call takers will now conference with police call takers under the modification to make sure all the information is correct. The change will be in place until officials decide it's not needed.