diff --git a/.gitignore b/.gitignore
index 38faf196d..045054eeb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 *~
+spack*
+Testing
 *.pyc
 *.root
 *.png
diff --git a/Generation/src/components/PythiaInterface.cpp b/Generation/src/components/PythiaInterface.cpp
index c96530dfa..3f0eeff58 100644
--- a/Generation/src/components/PythiaInterface.cpp
+++ b/Generation/src/components/PythiaInterface.cpp
@@ -103,7 +103,11 @@ StatusCode PythiaInterface::initialize() {
     }
 
     m_setting = std::unique_ptr<Pythia8::amcnlo_unitarised_interface>(new Pythia8::amcnlo_unitarised_interface(scheme));
+    #if PYTHIA_VERSION_INTEGER < 8300
     m_pythiaSignal->setUserHooksPtr(m_setting.get());
+    #else
+    m_pythiaSignal->setUserHooksPtr((Pythia8::UserHooksPtr) m_setting.get());
+    #endif
   }
 
   // For jet matching, initialise the respective user hooks code.
@@ -112,7 +116,11 @@ StatusCode PythiaInterface::initialize() {
     if (!m_matching) {
       return Error(" Failed to initialise jet matching structures.");
     }
+    #if PYTHIA_VERSION_INTEGER < 8300
     m_pythiaSignal->setUserHooksPtr(m_matching.get());
+    #else
+    m_pythiaSignal->setUserHooksPtr((Pythia8::UserHooksPtr) m_matching.get());
+    #endif
   }
 
   // jet clustering needed for matching
@@ -145,16 +153,25 @@ StatusCode PythiaInterface::initialize() {
 
     
     m_powhegHooks = std::make_shared<Pythia8::PowhegHooks>();
+    #if PYTHIA_VERSION_INTEGER < 8300
     m_pythiaSignal->addUserHooksPtr(m_powhegHooks.get());
+    #else
+    m_pythiaSignal->addUserHooksPtr((Pythia8::UserHooksPtr)m_powhegHooks.get());
+    #endif
   }
   bool resonanceDecayFilter = m_pythiaSignal->settings.flag("ResonanceDecayFilter:filter");
   if (resonanceDecayFilter) {
     m_resonanceDecayFilterHook = std::make_shared<ResonanceDecayFilterHook>();
+    #if PYTHIA_VERSION_INTEGER < 8300
     m_pythiaSignal->addUserHooksPtr(m_resonanceDecayFilterHook.get());
+    #else
+    m_pythiaSignal->addUserHooksPtr((Pythia8::UserHooksPtr)m_resonanceDecayFilterHook.get());
+    #endif
   }
 
   // Set up evtGen
   if (m_doEvtGenDecays) {
+    #if PYTHIA_VERSION_INTEGER < 8300
     m_evtgen = new EvtGenDecays(
                   m_pythiaSignal.get(), // the pythia instance 
                   m_EvtGenDecayFile.value(),  // the file name of the evtgen decay file
@@ -166,6 +183,19 @@ StatusCode PythiaInterface::initialize() {
 								  true, // a flag to limit decays based on the Pythia criteria (based on the particle decay vertex)
 								  true, // a flag to use external models with EvtGen
 								  false); // a flag if an FSR model should be passed to EvtGen (pay attention to this, default is true)
+    #else
+    m_evtgen = new Pythia8::EvtGenDecays(
+                  m_pythiaSignal.get(), // the pythia instance 
+                  m_EvtGenDecayFile.value(),  // the file name of the evtgen decay file
+                  m_EvtGenParticleDataFile.value(), // the file name of the evtgen data file
+								  nullptr, // the optional EvtExternalGenList pointer (must be be provided if the next argument is provided to avoid double initializations)
+								  nullptr, // the EvtAbsRadCorr pointer to pass to EvtGen
+								  1, // the mixing type to pass to EvtGen
+								  false, // a flag to use XML files to pass to EvtGen
+								  true, // a flag to limit decays based on the Pythia criteria (based on the particle decay vertex)
+								  true, // a flag to use external models with EvtGen
+								  false); // a flag if an FSR model should be passed to EvtGen (pay attention to this, default is true)
+    #endif
     if (!m_UserDecayFile.empty()) {
       m_evtgen->readDecayFile(m_UserDecayFile);
     }
diff --git a/Generation/src/components/PythiaInterface.h b/Generation/src/components/PythiaInterface.h
index 8a33ad0da..d5a7bf6ea 100644
--- a/Generation/src/components/PythiaInterface.h
+++ b/Generation/src/components/PythiaInterface.h
@@ -10,20 +10,31 @@
 #include "Pythia8Plugins/PowhegHooks.h"
 #include "Pythia8Plugins/HepMC2.h"
 
-class EvtGenDecays;
 
 // Forward HepMC
 namespace HepMC {
 class GenEvent;
 }
 // Forward Pythia
+#if PYTHIA_VERSION_INTEGER < 8300
+class EvtGenDecays;
+namespace Pythia8 {
+class Pythia;
+class SlowJet;
+class JetMatchingMadgraph;
+class amcnlo_unitarised_interface;
+}
+#else
 namespace Pythia8 {
+class EvtGenDecays;
 class Pythia;
 class SlowJet;
 class JetMatchingMadgraph;
 class amcnlo_unitarised_interface;
 }
 
+#endif
+
 namespace fcc {
   class FloatValueCollection;
 }
@@ -89,7 +100,11 @@ class PythiaInterface : public GaudiTool, virtual public IHepMCProviderTool {
 
   Gaudi::Property<std::vector<int>> m_evtGenExcludes{this, "EvtGenExcludes", {},
                                                            "Pdg IDs of particles not to decay with EvtGen"};
+  #if PYTHIA_VERSION_INTEGER < 8300
   EvtGenDecays* m_evtgen = nullptr;
+  #else
+  Pythia8::EvtGenDecays* m_evtgen = nullptr;
+  #endif
 };
 
 #endif  // GENERATION_PYTHIAINTERFACE_H