diff --git a/analyses/pluginLEP/L3_1997_I427107.cc b/analyses/pluginLEP/L3_1997_I427107.cc
--- a/analyses/pluginLEP/L3_1997_I427107.cc
+++ b/analyses/pluginLEP/L3_1997_I427107.cc
@@ -1,105 +1,106 @@
 // -*- C++ -*-
 #include "Rivet/Analysis.hh"
 #include "Rivet/Projections/FinalState.hh"
 #include "Rivet/Projections/FastJets.hh"
+#include "Rivet/Projections/UnstableParticles.hh"
 
 namespace Rivet {
 
 
   /// @brief eta' and omega production at mz
   class L3_1997_I427107 : public Analysis {
   public:
 
     /// Constructor
     DEFAULT_RIVET_ANALYSIS_CTOR(L3_1997_I427107);
 
 
     /// @name Analysis methods
     //@{
 
     /// Book histograms and initialise projections before the run
     void init() {
 
       // Initialise and register projections
       declare(Beam(), "Beams");
       declare(ChargedFinalState(), "FS");
       declare(UnstableParticles(), "UFS");
 
       // // Book histograms
       book(_histXpOmega  ,  5, 1, 1);
       book(_histLnXpOmega,  6, 1, 1);
       book(_histXpEtaP1  ,  7, 1, 1);
       book(_histLnXpEtaP1,  8, 1, 1);
       book(_histXpEtaP2  ,  9, 1, 1);
       book(_histLnXpEtaP2, 10, 1, 1);
 
     }
 
 
     /// Perform the per-event analysis
     void analyze(const Event& event) {
 
       // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.                                                    
       const FinalState& fs = apply<FinalState>(event, "FS");
       if (fs.particles().size() < 2) {
       	MSG_DEBUG("Failed ncharged cut");
       	vetoEvent;
       }
       MSG_DEBUG("Passed ncharged cut");
 
       // Get beams and average beam momentum                                                                                                
       const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
       const double meanBeamMom = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0;
       MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
 
       // Final state of unstable particles to get particle spectra
       const Particles& mesons = apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==PID::ETAPRIME or
       										 Cuts::pid==PID::OMEGA);
 
       for (const Particle& p : mesons) {
       	double xp = p.p3().mod()/meanBeamMom;
 	double xi = log(1./xp);
       	if(p.pid()==PID::ETAPRIME) {
       	  _histXpEtaP1->fill(xp);
       	  _histLnXpEtaP1->fill(xi);
       	  _histXpEtaP2->fill(xp);
       	  _histLnXpEtaP2->fill(xi);
       	}
       	else {
       	  _histXpOmega->fill(xp);
       	  _histLnXpOmega->fill(xi);
       	}
       }
     }
 
 
     /// Normalise histograms etc., after the run
     void finalize() {
       scale(_histXpEtaP1  , 1./sumOfWeights());
       scale(_histLnXpEtaP1, 1./sumOfWeights());
       scale(_histXpEtaP2  , 1./sumOfWeights());
       scale(_histLnXpEtaP2, 1./sumOfWeights());
       scale(_histXpOmega  , 1./sumOfWeights());
       scale(_histLnXpOmega, 1./sumOfWeights());
     }
 
     //@}
 
 
     /// @name Histograms
     //@{
     Histo1DPtr _histXpEtaP1,_histXpEtaP2;
     Histo1DPtr _histLnXpEtaP1,_histLnXpEtaP2;
     Histo1DPtr _histXpOmega;
     Histo1DPtr _histLnXpOmega;
     //@}
 
 
   };
 
 
   // The hook for the plugin system
   DECLARE_RIVET_PLUGIN(L3_1997_I427107);
 
 
 }