diff --git a/Framework/Cascade/Cascade.h b/Framework/Cascade/Cascade.h
index 75f29e4ed51bc70d7d31d4917ef4c186baee4bef..f9ec0beb0e40df08a16595bee6be8dc0048cff94 100644
--- a/Framework/Cascade/Cascade.h
+++ b/Framework/Cascade/Cascade.h
@@ -153,7 +153,7 @@ namespace corsika::cascade {
 
       // determine combined total interaction length (inverse)
       InverseGrammageType const total_inv_lambda =
-          fProcessSequence.GetTotalInverseInteractionLength(vParticle, step);
+          fProcessSequence.GetTotalInverseInteractionLength(vParticle);
 
       // sample random exponential step length in grammage
       corsika::random::ExponentialDistribution expDist(1 / total_inv_lambda);
@@ -242,13 +242,14 @@ namespace corsika::cascade {
         if (min_distance == distance_interact) {
           std::cout << "collide" << std::endl;
 
-          InverseGrammageType const actual_inv_length =
-              fProcessSequence.GetTotalInverseInteractionLength(vParticle, step);
+          InverseGrammageType const current_inv_length =
+              fProcessSequence.GetTotalInverseInteractionLength(vParticle);
 
-          random::UniformRealDistribution<InverseGrammageType> uniDist(actual_inv_length);
+          random::UniformRealDistribution<InverseGrammageType> uniDist(
+              current_inv_length);
           const auto sample_process = uniDist(fRNG);
           InverseGrammageType inv_lambda_count = 0. * meter * meter / gram;
-          fProcessSequence.SelectInteraction(vParticle, projectile, step, sample_process,
+          fProcessSequence.SelectInteraction(vParticle, projectile, sample_process,
                                              inv_lambda_count);
         } else if (min_distance == distance_decay) {
           std::cout << "decay" << std::endl;
diff --git a/Framework/Cascade/testCascade.cc b/Framework/Cascade/testCascade.cc
index 89fd65ef42150149a9c0ffbd7183fed865ba659d..f29d1af9fba4c01c6452fc2dc026df7ff99f2c42 100644
--- a/Framework/Cascade/testCascade.cc
+++ b/Framework/Cascade/testCascade.cc
@@ -69,8 +69,8 @@ public:
   ProcessSplit(GrammageType const X0)
       : fX0(X0) {}
 
-  template <typename Particle, typename Track>
-  corsika::units::si::GrammageType GetInteractionLength(Particle&, Track&) const {
+  template <typename Particle>
+  corsika::units::si::GrammageType GetInteractionLength(Particle const&) const {
     return fX0;
   }
 
diff --git a/Framework/ProcessSequence/InteractionProcess.h b/Framework/ProcessSequence/InteractionProcess.h
index 27ad9c222d5ce644d6b344a469edaf8e717fcf87..a9b4b9fca306e865a85ac94ae6a9878ce7f0057d 100644
--- a/Framework/ProcessSequence/InteractionProcess.h
+++ b/Framework/ProcessSequence/InteractionProcess.h
@@ -38,13 +38,12 @@ namespace corsika::process {
     template <typename Particle>
     EProcessReturn DoInteraction(Particle&);
 
-    template <typename Particle, typename Track>
-    corsika::units::si::GrammageType GetInteractionLength(Particle& p, Track& t);
+    template <typename TParticle>
+    corsika::units::si::GrammageType GetInteractionLength(TParticle& p);
 
-    template <typename Particle, typename Track>
-    corsika::units::si::InverseGrammageType GetInverseInteractionLength(Particle& p,
-                                                                        Track& t) {
-      return 1. / GetRef().GetInteractionLength(p, t);
+    template <typename TParticle>
+    corsika::units::si::InverseGrammageType GetInverseInteractionLength(TParticle& p) {
+      return 1. / GetRef().GetInteractionLength(p);
     }
   };
 
diff --git a/Framework/ProcessSequence/ProcessSequence.h b/Framework/ProcessSequence/ProcessSequence.h
index 3bd759c04a97e55360c87473cc4457159bd967fa..3e1e4e9a0202c2b67b454c5dfd89d05f29d37912 100644
--- a/Framework/ProcessSequence/ProcessSequence.h
+++ b/Framework/ProcessSequence/ProcessSequence.h
@@ -165,51 +165,49 @@ namespace corsika::process {
       return max_length;
     }
 
-    template <typename TParticle, typename TTrack>
-    corsika::units::si::GrammageType GetTotalInteractionLength(TParticle& vP,
-                                                               TTrack& vT) {
-      return 1. / GetInverseInteractionLength(vP, vT);
+    template <typename TParticle>
+    corsika::units::si::GrammageType GetTotalInteractionLength(TParticle& vP) {
+      return 1. / GetInverseInteractionLength(vP);
     }
 
-    template <typename TParticle, typename TTrack>
+    template <typename TParticle>
     corsika::units::si::InverseGrammageType GetTotalInverseInteractionLength(
-        TParticle& vP, TTrack& vT) {
-      return GetInverseInteractionLength(vP, vT);
+        TParticle& vP) {
+      return GetInverseInteractionLength(vP);
     }
 
-    template <typename TParticle, typename TTrack>
-    corsika::units::si::InverseGrammageType GetInverseInteractionLength(TParticle& vP,
-                                                                        TTrack& vT) {
+    template <typename TParticle>
+    corsika::units::si::InverseGrammageType GetInverseInteractionLength(TParticle& vP) {
       using namespace corsika::units::si;
 
       InverseGrammageType tot = 0 * meter * meter / gram;
 
-      if constexpr (std::is_base_of<InteractionProcess<T1type>, T1type>::value ||
-                    is_process_sequence<T1>::value) {
-        tot += A.GetInverseInteractionLength(vP, vT);
+      if constexpr (std::is_base_of_v<InteractionProcess<T1type>, T1type> ||
+                    is_process_sequence_v<T1>) {
+        tot += A.GetInverseInteractionLength(vP);
       }
-      if constexpr (std::is_base_of<InteractionProcess<T2type>, T2type>::value ||
-                    is_process_sequence<T2>::value) {
-        tot += B.GetInverseInteractionLength(vP, vT);
+      if constexpr (std::is_base_of_v<InteractionProcess<T2type>, T2type> ||
+                    is_process_sequence_v<T2>) {
+        tot += B.GetInverseInteractionLength(vP);
       }
       return tot;
     }
 
-    template <typename TParticle, typename TSecondaries, typename TTrack>
+    template <typename TParticle, typename TSecondaries>
     EProcessReturn SelectInteraction(
-        TParticle& vP, TSecondaries& vS, TTrack& vT,
+        TParticle& vP, TSecondaries& vS,
         [[maybe_unused]] corsika::units::si::InverseGrammageType lambda_select,
         corsika::units::si::InverseGrammageType& lambda_inv_count) {
 
       if constexpr (is_process_sequence<T1type>::value) {
         // if A is a process sequence --> check inside
         const EProcessReturn ret =
-            A.SelectInteraction(vP, vS, vT, lambda_select, lambda_inv_count);
+            A.SelectInteraction(vP, vS, lambda_select, lambda_inv_count);
         // if A did succeed, stop routine
         if (ret != EProcessReturn::eOk) { return ret; }
       } else if constexpr (std::is_base_of<InteractionProcess<T1type>, T1type>::value) {
         // if this is not a ContinuousProcess --> evaluate probability
-        lambda_inv_count += A.GetInverseInteractionLength(vP, vT);
+        lambda_inv_count += A.GetInverseInteractionLength(vP);
         // check if we should execute THIS process and then EXIT
         if (lambda_select < lambda_inv_count) {
           A.DoInteraction(vS);
@@ -220,12 +218,12 @@ namespace corsika::process {
       if constexpr (is_process_sequence<T2>::value) {
         // if A is a process sequence --> check inside
         const EProcessReturn ret =
-            B.SelectInteraction(vP, vS, vT, lambda_select, lambda_inv_count);
+            B.SelectInteraction(vP, vS, lambda_select, lambda_inv_count);
         // if A did succeed, stop routine
         if (ret != EProcessReturn::eOk) { return ret; }
       } else if constexpr (std::is_base_of<InteractionProcess<T2type>, T2type>::value) {
         // if this is not a ContinuousProcess --> evaluate probability
-        lambda_inv_count += B.GetInverseInteractionLength(vP, vT);
+        lambda_inv_count += B.GetInverseInteractionLength(vP);
         // check if we should execute THIS process and then EXIT
         if (lambda_select < lambda_inv_count) {
           B.DoInteraction(vS);
diff --git a/Framework/ProcessSequence/testProcessSequence.cc b/Framework/ProcessSequence/testProcessSequence.cc
index aa78ee89c4c012eb2df3d322b6b1ddf6fa44ba1e..e8bfe7c1c835762e64ccb3afed48962775dc24ae 100644
--- a/Framework/ProcessSequence/testProcessSequence.cc
+++ b/Framework/ProcessSequence/testProcessSequence.cc
@@ -100,8 +100,8 @@ public:
     cout << "Process2::DoInteraction" << endl;
     return EProcessReturn::eOk;
   }
-  template <typename Particle, typename Track>
-  GrammageType GetInteractionLength(Particle&, Track&) const {
+  template <typename Particle>
+  GrammageType GetInteractionLength(Particle&) const {
     cout << "Process2::GetInteractionLength" << endl;
     return 3_g / (1_cm * 1_cm);
   }
@@ -123,8 +123,8 @@ public:
     cout << "Process3::DoInteraction" << endl;
     return EProcessReturn::eOk;
   }
-  template <typename Particle, typename Track>
-  GrammageType GetInteractionLength(Particle&, Track&) const {
+  template <typename Particle>
+  GrammageType GetInteractionLength(Particle&) const {
     cout << "Process3::GetInteractionLength" << endl;
     return 1_g / (1_cm * 1_cm);
   }
@@ -220,12 +220,11 @@ TEST_CASE("Process Sequence", "[Process Sequence]") {
     Process3 m3(2);
 
     DummyData particle;
-    DummyTrajectory track;
 
     auto sequence2 = cp1 << m2 << m3;
-    GrammageType const tot = sequence2.GetTotalInteractionLength(particle, track);
+    GrammageType const tot = sequence2.GetTotalInteractionLength(particle);
     InverseGrammageType const tot_inv =
-        sequence2.GetTotalInverseInteractionLength(particle, track);
+        sequence2.GetTotalInverseInteractionLength(particle);
     cout << "lambda_tot=" << tot << "; lambda_tot_inv=" << tot_inv << endl;
   }
 
diff --git a/Processes/HadronicElasticModel/HadronicElasticModel.cc b/Processes/HadronicElasticModel/HadronicElasticModel.cc
index 33f162e41531bf4008f91b21bb98e8afc13a7abb..9e05c521320787b1f8a42ca3c154cfa708285769 100644
--- a/Processes/HadronicElasticModel/HadronicElasticModel.cc
+++ b/Processes/HadronicElasticModel/HadronicElasticModel.cc
@@ -18,14 +18,12 @@
 #include <corsika/utl/COMBoost.h>
 
 #include <corsika/setup/SetupStack.h>
-#include <corsika/setup/SetupTrajectory.h>
 
 #include <iomanip>
 #include <iostream>
 
 using namespace corsika::setup;
-using Particle = corsika::setup::Stack::ParticleType;
-using Track = corsika::setup::Trajectory;
+using SetupParticle = corsika::setup::Stack::ParticleType;
 
 namespace corsika::process::HadronicElasticModel {
 
@@ -38,7 +36,7 @@ namespace corsika::process::HadronicElasticModel {
 
   template <>
   units::si::GrammageType HadronicElasticInteraction::GetInteractionLength(
-      Particle const& p, Track&) {
+      SetupParticle const& p) {
     using namespace units::si;
     if (p.GetPID() == particles::Code::Proton) {
       auto const* currentNode = p.GetNode();
@@ -79,7 +77,7 @@ namespace corsika::process::HadronicElasticModel {
   }
 
   template <>
-  process::EProcessReturn HadronicElasticInteraction::DoInteraction(Particle& p) {
+  process::EProcessReturn HadronicElasticInteraction::DoInteraction(SetupParticle& p) {
     if (p.GetPID() != particles::Code::Proton) { return process::EProcessReturn::eOk; }
 
     using namespace units::si;
diff --git a/Processes/HadronicElasticModel/HadronicElasticModel.h b/Processes/HadronicElasticModel/HadronicElasticModel.h
index 4180c04c514d00089fd044ab39027b9128a853ff..b3fd15fd2cdc6feac967182cff342b60f30e954d 100644
--- a/Processes/HadronicElasticModel/HadronicElasticModel.h
+++ b/Processes/HadronicElasticModel/HadronicElasticModel.h
@@ -56,8 +56,8 @@ namespace corsika::process::HadronicElasticModel {
         units::si::CrossSectionType y = 0.05608 * units::si::barn);
     void Init();
 
-    template <typename Particle, typename Track>
-    corsika::units::si::GrammageType GetInteractionLength(Particle const& p, Track&);
+    template <typename Particle>
+    corsika::units::si::GrammageType GetInteractionLength(Particle const& p);
 
     template <typename Particle>
     corsika::process::EProcessReturn DoInteraction(Particle&);
diff --git a/Processes/Pythia/Interaction.cc b/Processes/Pythia/Interaction.cc
index 6cdf54973a2d553a79f6b6ebcd97b4d5ecf6cf24..2a0cce386edc6dfc5a14f0f6fb84fd94aa5a85a7 100644
--- a/Processes/Pythia/Interaction.cc
+++ b/Processes/Pythia/Interaction.cc
@@ -15,7 +15,6 @@
 #include <corsika/environment/NuclearComposition.h>
 #include <corsika/geometry/FourVector.h>
 #include <corsika/setup/SetupStack.h>
-#include <corsika/setup/SetupTrajectory.h>
 #include <corsika/utl/COMBoost.h>
 
 #include <tuple>
@@ -28,7 +27,6 @@ using namespace corsika;
 using namespace corsika::setup;
 using Projectile = corsika::setup::StackView::ParticleType;
 using Particle = corsika::setup::Stack::ParticleType;
-using Track = Trajectory;
 
 namespace corsika::process::pythia {
 
@@ -168,7 +166,7 @@ namespace corsika::process::pythia {
   }
 
   template <>
-  units::si::GrammageType Interaction::GetInteractionLength(Particle& p, Track&) {
+  units::si::GrammageType Interaction::GetInteractionLength(Particle& p) {
 
     using namespace units;
     using namespace units::si;
diff --git a/Processes/Pythia/Interaction.h b/Processes/Pythia/Interaction.h
index ac27825acf0561d0d9e7e8e8b66961bdfc674e2f..3594358e0b39f528991183b4c414e8edaa3b5828 100644
--- a/Processes/Pythia/Interaction.h
+++ b/Processes/Pythia/Interaction.h
@@ -51,16 +51,16 @@ namespace corsika::process::pythia {
                     const corsika::particles::Code TargetId,
                     const corsika::units::si::HEPEnergyType CoMenergy);
 
-    template <typename TParticle, typename TTrack>
-    corsika::units::si::GrammageType GetInteractionLength(TParticle&, TTrack&);
+    template <typename TParticle>
+    corsika::units::si::GrammageType GetInteractionLength(TParticle&);
 
     /**
        In this function PYTHIA is called to produce one event. The
        event is copied (and boosted) into the shower lab frame.
      */
 
-    template <typename TProjctile>
-    corsika::process::EProcessReturn DoInteraction(TProjctile&);
+    template <typename TProjectile>
+    corsika::process::EProcessReturn DoInteraction(TProjectile&);
 
   private:
     corsika::random::RNG& fRNG =
diff --git a/Processes/Pythia/testPythia.cc b/Processes/Pythia/testPythia.cc
index 3fb2df13ecd1c24e674997a3c3aa468164f21d06..f6f09b84c17f80f8b579d1a11eba843e6ddbc964 100644
--- a/Processes/Pythia/testPythia.cc
+++ b/Processes/Pythia/testPythia.cc
@@ -118,14 +118,6 @@ TEST_CASE("pythia process") {
   auto const* nodePtr = theMedium.get(); // save the medium for later use before moving it
   universe.AddChild(std::move(theMedium));
 
-  geometry::Point const origin(cs, {0_m, 0_m, 0_m});
-  geometry::Vector<units::si::SpeedType::dimension_type> v(cs, 0_m / second, 0_m / second,
-                                                           1_m / second);
-  geometry::Line line(origin, v);
-  geometry::Trajectory<geometry::Line> track(line, 10_s);
-
-  random::RNGManager::GetInstance().RegisterRandomStream("s_rndm");
-
   SECTION("pythia decay") {
 
     setup::Stack stack;
@@ -173,7 +165,6 @@ TEST_CASE("pythia process") {
     process::pythia::Interaction model;
     model.Init();
     [[maybe_unused]] const process::EProcessReturn ret = model.DoInteraction(projectile);
-    [[maybe_unused]] const GrammageType length =
-        model.GetInteractionLength(particle, track);
+    [[maybe_unused]] const GrammageType length = model.GetInteractionLength(particle);
   }
 }
diff --git a/Processes/Sibyll/Interaction.cc b/Processes/Sibyll/Interaction.cc
index b15d9e8859e86d6426f6b78b7834fe2211f191f1..c089ec083c9c7d9ec1d91136cb0c7796dc958c57 100644
--- a/Processes/Sibyll/Interaction.cc
+++ b/Processes/Sibyll/Interaction.cc
@@ -118,8 +118,8 @@ namespace corsika::process::sibyll {
   }
 
   template <>
-  units::si::GrammageType Interaction::GetInteractionLength(SetupParticle& vP,
-                                                            Track&) const {
+  units::si::GrammageType Interaction::GetInteractionLength(
+      SetupParticle const& vP) const {
 
     using namespace units;
     using namespace units::si;
diff --git a/Processes/Sibyll/Interaction.h b/Processes/Sibyll/Interaction.h
index e7d7a0902116c2fceb9240cf9266d04a2ea2fd72..643bd0d51bd4f387aafa3870f2dddfb0ed1fe9d5 100644
--- a/Processes/Sibyll/Interaction.h
+++ b/Processes/Sibyll/Interaction.h
@@ -52,8 +52,8 @@ namespace corsika::process::sibyll {
     GetCrossSection(const corsika::particles::Code, const corsika::particles::Code,
                     const corsika::units::si::HEPEnergyType) const;
 
-    template <typename TParticle, typename TTrack>
-    corsika::units::si::GrammageType GetInteractionLength(TParticle&, TTrack&) const;
+    template <typename TParticle>
+    corsika::units::si::GrammageType GetInteractionLength(TParticle const&) const;
 
     /**
        In this function SIBYLL is called to produce one event. The
diff --git a/Processes/Sibyll/NuclearInteraction.cc b/Processes/Sibyll/NuclearInteraction.cc
index 31abd9da350e1c80c24868eb2313e860b51bd821..907e95b271bb44cfb4d2982f0f1f40f88cbb0eca 100644
--- a/Processes/Sibyll/NuclearInteraction.cc
+++ b/Processes/Sibyll/NuclearInteraction.cc
@@ -217,7 +217,7 @@ namespace corsika::process::sibyll {
   template <>
   template <>
   units::si::GrammageType NuclearInteraction<SetupEnvironment>::GetInteractionLength(
-      Particle& vP, Track&) {
+      Particle& vP) {
 
     using namespace units;
     using namespace units::si;
diff --git a/Processes/Sibyll/NuclearInteraction.h b/Processes/Sibyll/NuclearInteraction.h
index 6bee9ba7a7964e74112c2bf60e5cbd4b1c23c2fa..261f931321ed98119ab02f4e3cace952308fdbb7 100644
--- a/Processes/Sibyll/NuclearInteraction.h
+++ b/Processes/Sibyll/NuclearInteraction.h
@@ -53,11 +53,11 @@ namespace corsika::process::sibyll {
     std::tuple<corsika::units::si::CrossSectionType, corsika::units::si::CrossSectionType>
     GetCrossSection(Particle& p, const corsika::particles::Code TargetId);
 
-    template <typename Particle, typename Track>
-    corsika::units::si::GrammageType GetInteractionLength(Particle&, Track&);
+    template <typename Particle>
+    corsika::units::si::GrammageType GetInteractionLength(Particle&);
 
-    template <typename Projectle>
-    corsika::process::EProcessReturn DoInteraction(Projectle&);
+    template <typename Projectile>
+    corsika::process::EProcessReturn DoInteraction(Projectile&);
 
   private:
     TEnvironment const& fEnvironment;
diff --git a/Processes/Sibyll/testSibyll.cc b/Processes/Sibyll/testSibyll.cc
index d5f5d9bc8e39ac775de3fb9d541a18b596941bad..0c42c90abb86a758c45f5ad4a79ebe87d3f1d3fa 100644
--- a/Processes/Sibyll/testSibyll.cc
+++ b/Processes/Sibyll/testSibyll.cc
@@ -98,12 +98,6 @@ TEST_CASE("SibyllInterface", "[processes]") {
 
   const geometry::CoordinateSystem& cs = env.GetCoordinateSystem();
 
-  geometry::Point const origin(cs, {0_m, 0_m, 0_m});
-  geometry::Vector<units::si::SpeedType::dimension_type> v(cs, 0_m / second, 0_m / second,
-                                                           1_m / second);
-  geometry::Line line(origin, v);
-  geometry::Trajectory<geometry::Line> track(line, 10_s);
-
   random::RNGManager::GetInstance().RegisterRandomStream("s_rndm");
 
   SECTION("InteractionInterface") {
@@ -126,8 +120,7 @@ TEST_CASE("SibyllInterface", "[processes]") {
 
     model.Init();
     [[maybe_unused]] const process::EProcessReturn ret = model.DoInteraction(projectile);
-    [[maybe_unused]] const GrammageType length =
-        model.GetInteractionLength(particle, track);
+    [[maybe_unused]] const GrammageType length = model.GetInteractionLength(particle);
   }
 
   SECTION("NuclearInteractionInterface") {
@@ -153,8 +146,7 @@ TEST_CASE("SibyllInterface", "[processes]") {
 
     model.Init();
     [[maybe_unused]] const process::EProcessReturn ret = model.DoInteraction(projectile);
-    [[maybe_unused]] const GrammageType length =
-        model.GetInteractionLength(particle, track);
+    [[maybe_unused]] const GrammageType length = model.GetInteractionLength(particle);
   }
 
   SECTION("DecayInterface") {
diff --git a/Processes/UrQMD/UrQMD.cc b/Processes/UrQMD/UrQMD.cc
index df4456bfb965f398720e33aafd286ed56bbdb307..98f7a7385727d30836e7590bfb6bd54f8de4f542 100644
--- a/Processes/UrQMD/UrQMD.cc
+++ b/Processes/UrQMD/UrQMD.cc
@@ -2,9 +2,6 @@
 #include <corsika/geometry/Vector.h>
 #include <corsika/particles/ParticleProperties.h>
 #include <corsika/process/urqmd/UrQMD.h>
-#include <corsika/random/RNGManager.h>
-#include <corsika/setup/SetupStack.h>
-#include <corsika/setup/SetupTrajectory.h>
 #include <corsika/units/PhysicalUnits.h>
 
 #include <algorithm>
@@ -20,7 +17,6 @@ UrQMD::UrQMD() { iniurqmd_(); }
 using SetupStack = corsika::setup::Stack;
 using SetupParticle = corsika::setup::Stack::StackIterator;
 using SetupProjectile = corsika::setup::StackView::StackIterator;
-using SetupTrack = corsika::setup::Trajectory;
 
 template <typename TParticle> // need template here, as this is called both with
                               // SetupParticle as well as SetupProjectile
@@ -82,7 +78,7 @@ bool UrQMD::CanInteract(particles::Code vCode) const {
                    vCode) != std::cend(validProjectileCodes);
 }
 
-GrammageType UrQMD::GetInteractionLength(SetupParticle& vParticle, SetupTrack&) const {
+GrammageType UrQMD::GetInteractionLength(SetupParticle& vParticle) const {
   if (!CanInteract(vParticle.GetPID())) {
     // we could do the canInteract check in GetCrossSection, too but if
     // we do it here we have the advantage of avoiding the loop
diff --git a/Processes/UrQMD/UrQMD.h b/Processes/UrQMD/UrQMD.h
index 11c8a0eb9a14268f1729a2fbf23508bcf024bcb4..a77e6e843b38055bc96c470c79f2902fcfa58ce5 100644
--- a/Processes/UrQMD/UrQMD.h
+++ b/Processes/UrQMD/UrQMD.h
@@ -5,7 +5,6 @@
 #include <corsika/process/InteractionProcess.h>
 #include <corsika/random/RNGManager.h>
 #include <corsika/setup/SetupStack.h>
-#include <corsika/setup/SetupTrajectory.h>
 #include <corsika/units/PhysicalUnits.h>
 
 #include <array>
@@ -17,7 +16,7 @@ namespace corsika::process::UrQMD {
     UrQMD();
     void Init() {}
     corsika::units::si::GrammageType GetInteractionLength(
-        corsika::setup::Stack::StackIterator&, corsika::setup::Trajectory&) const;
+        corsika::setup::Stack::StackIterator&) const;
 
     template <typename TParticle>
     corsika::units::si::CrossSectionType GetCrossSection(TParticle const&,