diff --git a/analyzers/dataframe/FCCAnalyses/JetConstituentsUtils.h b/analyzers/dataframe/FCCAnalyses/JetConstituentsUtils.h
index 8db72cb9f4..7d2f40a878 100644
--- a/analyzers/dataframe/FCCAnalyses/JetConstituentsUtils.h
+++ b/analyzers/dataframe/FCCAnalyses/JetConstituentsUtils.h
@@ -252,7 +252,11 @@ namespace FCCAnalyses {
     rv::RVec<TLorentzVector> compute_tlv_jets(const rv::RVec<fastjet::PseudoJet>& jets);
     rv::RVec<TLorentzVector> sum_tlv_constituents(const rv::RVec<FCCAnalysesJetConstituents>& jets);
     float InvariantMass(const TLorentzVector& tlv1, const TLorentzVector& tlv2);
-    rv::RVec<double> all_invariant_masses(rv::RVec<TLorentzVector> AllJets); // invariant masses of all jet pairs given a vector of jets
+    
+    /**
+     * @brief all_invariant_masses takes an RVec of TLorentzVectors of jets and computes the invariant masses of all jet pairs, and returns an RVec with all invariant masses.
+    */
+    rv::RVec<double> all_invariant_masses(rv::RVec<TLorentzVector> AllJets);
     rv::RVec<double> compute_residue_energy(const rv::RVec<TLorentzVector>& tlv_jet,
 					    const rv::RVec<TLorentzVector>& sum_tlv_jcs);
     rv::RVec<double> compute_residue_pt(const rv::RVec<TLorentzVector>& tlv_jet,
diff --git a/analyzers/dataframe/src/JetConstituentsUtils.cc b/analyzers/dataframe/src/JetConstituentsUtils.cc
index 0fead9fa72..f339920219 100644
--- a/analyzers/dataframe/src/JetConstituentsUtils.cc
+++ b/analyzers/dataframe/src/JetConstituentsUtils.cc
@@ -1269,6 +1269,8 @@ namespace FCCAnalyses
       
       rv::RVec<double> InvariantMasses;
 
+      if(AllJets.size() < 2) return InvariantMasses;
+
       // For each jet, take its invariant mass with the remaining jets. Stop at last jet.
       for(int i = 0; i < AllJets.size()-1; ++i) {