diff --git a/Processes/Sibyll/SibStack.h b/Processes/Sibyll/SibStack.h
index d78273822c700edaaae9e2c6bbefdfbfabb2a9e8..9d395c19bb6f178d9eb1b4c9573da8f4c3a7d514 100644
--- a/Processes/Sibyll/SibStack.h
+++ b/Processes/Sibyll/SibStack.h
@@ -28,6 +28,11 @@ namespace corsika::process::sibyll {
       using namespace corsika::units::hep;
       s_plist_.p[3][i] = v / 1_GeV;
     }
+    void SetMass(const int i, const corsika::units::hep::MassType v) {
+      using namespace corsika::units::hep;
+      s_plist_.p[4][i] = v / 1_GeV;
+    }
+
     void SetMomentum(const int i, const MomentumVector& v) {
       using namespace corsika::units;
       using namespace corsika::units::hep;
@@ -41,6 +46,10 @@ namespace corsika::process::sibyll {
       using namespace corsika::units::hep;
       return s_plist_.p[3][i] * 1_GeV;
     }
+    corsika::units::hep::EnergyType GetMass(const int i) const {
+      using namespace corsika::units::hep;
+      return s_plist_.p[4][i] * 1_GeV;
+    }
 
     MomentumVector GetMomentum(const int i) const {
       using corsika::geometry::CoordinateSystem;
@@ -80,6 +89,12 @@ namespace corsika::process::sibyll {
     corsika::units::hep::EnergyType GetEnergy() const {
       return GetStackData().GetEnergy(GetIndex());
     }
+    void SetMass(const corsika::units::hep::MassType v) {
+      GetStackData().SetMass(GetIndex(), v);
+    }
+    corsika::units::hep::EnergyType GetMass() const {
+      return GetStackData().GetMass(GetIndex());
+    }
     bool HasDecayed() const
     {
       return abs(GetStackData().GetId(GetIndex()))>100 ? true : false;