Dispersal orders will continue to be used across Derby's city centre because they have been so effective.
The orders allow officers to split up groups of people deemed to be causing trouble but are time-limited.
Since the idea was introduced, Derby has been one of the few cities to see a reduction in violent crime but the trial period was due to end in January.
Dispersal orders will now be used in and around the city centre until the end of July.
Figures show crime, especially alcohol related offences, have reduced by 15% compared to the same time last year.