© 2019 Elsevier B.V. In this work, we present a multi-peak fitting code in order to establish a new protocol for the analysis of γ spectra at ISIS pulsed Neutron and Muon Source. The protocol, relying on the ROOT framework developed at CERN, has been tailored for the analysis of two specific gamma emitters – 241Am and 133Ba – and its results have been compared to those generated by Hypermet PC, a dedicated software package specifically devoted to the analysis of neutron induced γ-ray spectra and of widespread use since late 1990s. This new fitting procedure is scheduled for integration into the software for time-resolved prompt-gamma activation analysis, T-PGAA, currently under development at ISIS. T-PGAA allows for the simultaneous acquisition of photon energy and neutron time of flight, respectively, when prompt gamma rays are emitted by a sample after neutron absorption, essentially combining neutron resonance capture analysis (NRCA) and prompt gamma activation analysis (PGAA).