diff --git a/projects/dataclasses/private/InteractionRecord.cxx b/projects/dataclasses/private/InteractionRecord.cxx
index 3000d82b..51d5e2d7 100644
--- a/projects/dataclasses/private/InteractionRecord.cxx
+++ b/projects/dataclasses/private/InteractionRecord.cxx
@@ -21,6 +21,10 @@ ParticleID const & InteractionRecord::GetPrimaryID() const {
     return primary_id;
 }
 
+ParticleType const & InteractionRecord::GetPrimaryType() const {
+    return signature.primary_type;
+}
+
 std::array<double, 3> const & InteractionRecord::GetPrimaryInitialPosition() const {
     return primary_initial_position;
 }
diff --git a/projects/dataclasses/public/LeptonInjector/dataclasses/InteractionRecord.h b/projects/dataclasses/public/LeptonInjector/dataclasses/InteractionRecord.h
index a489645e..bdeb1146 100644
--- a/projects/dataclasses/public/LeptonInjector/dataclasses/InteractionRecord.h
+++ b/projects/dataclasses/public/LeptonInjector/dataclasses/InteractionRecord.h
@@ -65,6 +65,7 @@ class InteractionRecord {
 
     Particle GetPrimary() const;
     ParticleID const & GetPrimaryID() const;
+    ParticleType const & GetPrimaryType() const;
     std::array<double, 3> const & GetPrimaryInitialPosition() const;
     double const & GetPrimaryMass() const;
     std::array<double, 4> const & GetPrimaryMomentum() const;
diff --git a/projects/interactions/private/Decay.cxx b/projects/interactions/private/Decay.cxx
index f9655667..7234649b 100644
--- a/projects/interactions/private/Decay.cxx
+++ b/projects/interactions/private/Decay.cxx
@@ -22,13 +22,15 @@ bool Decay::operator==(Decay const & other) const {
 
 double Decay::TotalDecayLength(dataclasses::InteractionRecord const & interaction) const {
     double tau = 1./TotalDecayWidth(interaction); // in inverse GeV
-    rk::P4 p1(geom3::Vector3(interaction.primary_momentum[1], interaction.primary_momentum[2], interaction.primary_momentum[3]), interaction.primary_mass);
+    std::array<double, 4> p4 = interaction.GetPrimaryMomentum();
+    rk::P4 p1(geom3::Vector3(p4[1], p4[2], p4[3]), interaction.GetPrimaryMass());
     return p1.beta() * p1.gamma() * tau * LI::utilities::Constants::hbarc;
 }
 
 double Decay::TotalDecayLengthForFinalState(dataclasses::InteractionRecord const & interaction) const {
     double tau = 1./TotalDecayWidthForFinalState(interaction); // in inverse GeV
-    rk::P4 p1(geom3::Vector3(interaction.primary_momentum[1], interaction.primary_momentum[2], interaction.primary_momentum[3]), interaction.primary_mass);
+    std::array<double, 4> p4 = interaction.GetPrimaryMomentum();
+    rk::P4 p1(geom3::Vector3(p4[1], p4[2], p4[3]), interaction.GetPrimaryMass());
     return p1.beta() * p1.gamma() * tau * LI::utilities::Constants::hbarc;
 }
 
diff --git a/projects/interactions/private/InteractionCollection.cxx b/projects/interactions/private/InteractionCollection.cxx
index 4747f8e0..2ce86bbe 100644
--- a/projects/interactions/private/InteractionCollection.cxx
+++ b/projects/interactions/private/InteractionCollection.cxx
@@ -95,7 +95,7 @@ double InteractionCollection::TotalDecayLength(dataclasses::InteractionRecord co
 }
 
 bool InteractionCollection::MatchesPrimary(dataclasses::InteractionRecord const & record) const {
-    return primary_type == record.signature.primary_type;
+    return primary_type == record.GetPrimaryType();
 }
 
 } // namespace interactions
diff --git a/projects/interactions/public/LeptonInjector/interactions/CrossSection.h b/projects/interactions/public/LeptonInjector/interactions/CrossSection.h
index 6a1ea388..12c6afa3 100644
--- a/projects/interactions/public/LeptonInjector/interactions/CrossSection.h
+++ b/projects/interactions/public/LeptonInjector/interactions/CrossSection.h
@@ -16,7 +16,7 @@
 
 #include "LeptonInjector/dataclasses/Particle.h"  // for Particle
 
-namespace LI { namespace dataclasses { struct InteractionRecord; } }
+namespace LI { namespace dataclasses { class InteractionRecord; } }
 namespace LI { namespace dataclasses { struct InteractionSignature; } }
 namespace LI { namespace utilities { class LI_random; } }
 
diff --git a/projects/interactions/public/LeptonInjector/interactions/Decay.h b/projects/interactions/public/LeptonInjector/interactions/Decay.h
index c5d1de34..a42a6ec7 100644
--- a/projects/interactions/public/LeptonInjector/interactions/Decay.h
+++ b/projects/interactions/public/LeptonInjector/interactions/Decay.h
@@ -16,7 +16,7 @@
 
 #include "LeptonInjector/dataclasses/Particle.h"  // for Particle
 
-namespace LI { namespace dataclasses { struct InteractionRecord; } }
+namespace LI { namespace dataclasses { class InteractionRecord; } }
 namespace LI { namespace dataclasses { struct InteractionSignature; } }
 namespace LI { namespace utilities { class LI_random; } }
 
diff --git a/projects/interactions/public/LeptonInjector/interactions/DipoleFromTable.h b/projects/interactions/public/LeptonInjector/interactions/DipoleFromTable.h
index 1d57dafe..0d6d5b9e 100644
--- a/projects/interactions/public/LeptonInjector/interactions/DipoleFromTable.h
+++ b/projects/interactions/public/LeptonInjector/interactions/DipoleFromTable.h
@@ -23,7 +23,7 @@
 #include "LeptonInjector/dataclasses/Particle.h"        // for Particle
 #include "LeptonInjector/utilities/Interpolator.h"      // for Interpolator1D
 
-namespace LI { namespace dataclasses { struct InteractionRecord; } }
+namespace LI { namespace dataclasses { class InteractionRecord; } }
 namespace LI { namespace dataclasses { struct InteractionSignature; } }
 namespace LI { namespace utilities { class LI_random; } }
 
diff --git a/projects/interactions/public/LeptonInjector/interactions/InteractionCollection.h b/projects/interactions/public/LeptonInjector/interactions/InteractionCollection.h
index ca57cf84..9c5278ea 100644
--- a/projects/interactions/public/LeptonInjector/interactions/InteractionCollection.h
+++ b/projects/interactions/public/LeptonInjector/interactions/InteractionCollection.h
@@ -27,7 +27,7 @@
 
 namespace LI { namespace interactions { class CrossSection; } }
 namespace LI { namespace interactions { class Decay; } }
-namespace LI { namespace dataclasses { struct InteractionRecord; } }
+namespace LI { namespace dataclasses { class InteractionRecord; } }
 
 namespace LI {
 namespace interactions {