diff --git a/benchmarks/dvmp/analysis/vm_invar.cxx b/benchmarks/dvmp/analysis/vm_invar.cxx
index 83723c5a64bbeb68efdc70026775bb40c6899185..296b7ed412f196669ad7c5c242ed1eeb0d4b0210 100644
--- a/benchmarks/dvmp/analysis/vm_invar.cxx
+++ b/benchmarks/dvmp/analysis/vm_invar.cxx
@@ -74,6 +74,10 @@ int vm_invar(const std::string& config_name)
     return util::momenta_from_tracking(tracks, decay_mass);
   };
 
+  auto calc_inv_quant_rec = [vm_mass](const std::vector<ROOT::Math::PxPyPzMVector>& parts) {
+    return util::calc_inv_quant_rec(parts, vm_mass);
+  };
+
   //====================================================================
 
   // Define analysis flow
diff --git a/include/util.h b/include/util.h
index 56fb12893787e1d1fff00bd01653ad23b149f48e..6a24b293c26963b4999fc63df821ab3418c694a8 100644
--- a/include/util.h
+++ b/include/util.h
@@ -48,6 +48,8 @@ namespace util {
       return 3.0969;
     } else if (part == "upsilon") {
       return 9.49630;
+    } else if (part == "proton"){
+      return 0.938272;
     } else {
       throw unknown_particle_error{part};
     }