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) {