diff --git a/CMakeLists.txt b/CMakeLists.txt
index 47676b7..7e65615 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,7 +29,7 @@ add_subdirectory(external/awkward/header-only)
 add_subdirectory(external/pybind11)
 
 file(GLOB_RECURSE SOURCES CONFIGURE_DEPENDS
-     "${PROJECT_SOURCE_DIR}/src/geant4/*.cpp")
+     "${PROJECT_SOURCE_DIR}/src/geant4_application/src/*.cpp")
 
 file(GLOB_RECURSE PYTHON_SOURCES CONFIGURE_DEPENDS
      "${PROJECT_SOURCE_DIR}/src/python/*.cpp")
@@ -42,7 +42,7 @@ target_compile_definitions(
                                   )
 
 target_include_directories(
-    ${PYTHON_MODULE_NAME} PRIVATE ${PROJECT_SOURCE_DIR}/include
+    ${PYTHON_MODULE_NAME} PRIVATE ${PROJECT_SOURCE_DIR}/src/geant4_application/include
                                   ${Geant4_INCLUDE_DIRS})
 
 target_link_libraries(
diff --git a/include/geant4/ActionInitialization.h b/src/geant4_application/include/geant4_application/ActionInitialization.h
similarity index 100%
rename from include/geant4/ActionInitialization.h
rename to src/geant4_application/include/geant4_application/ActionInitialization.h
diff --git a/include/geant4/Application.h b/src/geant4_application/include/geant4_application/Application.h
similarity index 90%
rename from include/geant4/Application.h
rename to src/geant4_application/include/geant4_application/Application.h
index 1f7bfc5..2d00798 100644
--- a/include/geant4/Application.h
+++ b/src/geant4_application/include/geant4_application/Application.h
@@ -10,9 +10,9 @@
 #include "pybind11/pybind11.h"
 #include "pybind11/stl.h"
 
-#include "geant4/DetectorConstruction.h"
-#include "geant4/PrimaryGeneratorAction.h"
-#include "geant4/StackingAction.h"
+#include "geant4_application/DetectorConstruction.h"
+#include "geant4_application/PrimaryGeneratorAction.h"
+#include "geant4_application/StackingAction.h"
 
 namespace py = pybind11;
 
diff --git a/include/geant4/DataModel.h b/src/geant4_application/include/geant4_application/DataModel.h
similarity index 100%
rename from include/geant4/DataModel.h
rename to src/geant4_application/include/geant4_application/DataModel.h
diff --git a/include/geant4/DetectorConstruction.h b/src/geant4_application/include/geant4_application/DetectorConstruction.h
similarity index 100%
rename from include/geant4/DetectorConstruction.h
rename to src/geant4_application/include/geant4_application/DetectorConstruction.h
diff --git a/include/geant4/EventAction.h b/src/geant4_application/include/geant4_application/EventAction.h
similarity index 100%
rename from include/geant4/EventAction.h
rename to src/geant4_application/include/geant4_application/EventAction.h
diff --git a/include/geant4/PhysicsList.h b/src/geant4_application/include/geant4_application/PhysicsList.h
similarity index 100%
rename from include/geant4/PhysicsList.h
rename to src/geant4_application/include/geant4_application/PhysicsList.h
diff --git a/include/geant4/PrimaryGeneratorAction.h b/src/geant4_application/include/geant4_application/PrimaryGeneratorAction.h
similarity index 100%
rename from include/geant4/PrimaryGeneratorAction.h
rename to src/geant4_application/include/geant4_application/PrimaryGeneratorAction.h
diff --git a/include/geant4/RunAction.h b/src/geant4_application/include/geant4_application/RunAction.h
similarity index 92%
rename from include/geant4/RunAction.h
rename to src/geant4_application/include/geant4_application/RunAction.h
index fb2bc02..2ff4947 100644
--- a/include/geant4/RunAction.h
+++ b/src/geant4_application/include/geant4_application/RunAction.h
@@ -4,7 +4,7 @@
 #include <G4RunManager.hh>
 #include <G4UserRunAction.hh>
 
-#include "geant4/DataModel.h"
+#include "geant4_application/DataModel.h"
 
 namespace geant4_app {
 
diff --git a/include/geant4/SensitiveDetector.h b/src/geant4_application/include/geant4_application/SensitiveDetector.h
similarity index 100%
rename from include/geant4/SensitiveDetector.h
rename to src/geant4_application/include/geant4_application/SensitiveDetector.h
diff --git a/include/geant4/StackingAction.h b/src/geant4_application/include/geant4_application/StackingAction.h
similarity index 100%
rename from include/geant4/StackingAction.h
rename to src/geant4_application/include/geant4_application/StackingAction.h
diff --git a/include/geant4/SteppingAction.h b/src/geant4_application/include/geant4_application/SteppingAction.h
similarity index 100%
rename from include/geant4/SteppingAction.h
rename to src/geant4_application/include/geant4_application/SteppingAction.h
diff --git a/include/geant4/SteppingVerbose.h b/src/geant4_application/include/geant4_application/SteppingVerbose.h
similarity index 100%
rename from include/geant4/SteppingVerbose.h
rename to src/geant4_application/include/geant4_application/SteppingVerbose.h
diff --git a/include/geant4/TrackingAction.h b/src/geant4_application/include/geant4_application/TrackingAction.h
similarity index 100%
rename from include/geant4/TrackingAction.h
rename to src/geant4_application/include/geant4_application/TrackingAction.h
diff --git a/src/geant4/ActionInitialization.cpp b/src/geant4_application/src/ActionInitialization.cpp
similarity index 67%
rename from src/geant4/ActionInitialization.cpp
rename to src/geant4_application/src/ActionInitialization.cpp
index 4067d35..a296ebc 100644
--- a/src/geant4/ActionInitialization.cpp
+++ b/src/geant4_application/src/ActionInitialization.cpp
@@ -1,12 +1,12 @@
 
-#include "geant4/ActionInitialization.h"
-#include "geant4/EventAction.h"
-#include "geant4/PrimaryGeneratorAction.h"
-#include "geant4/RunAction.h"
-#include "geant4/StackingAction.h"
-#include "geant4/SteppingAction.h"
-#include "geant4/SteppingVerbose.h"
-#include "geant4/TrackingAction.h"
+#include "geant4_application/ActionInitialization.h"
+#include "geant4_application/EventAction.h"
+#include "geant4_application/PrimaryGeneratorAction.h"
+#include "geant4_application/RunAction.h"
+#include "geant4_application/StackingAction.h"
+#include "geant4_application/SteppingAction.h"
+#include "geant4_application/SteppingVerbose.h"
+#include "geant4_application/TrackingAction.h"
 
 #include <iostream>
 
diff --git a/src/geant4/Application.cpp b/src/geant4_application/src/Application.cpp
similarity index 95%
rename from src/geant4/Application.cpp
rename to src/geant4_application/src/Application.cpp
index 7afb0be..4f2be3b 100644
--- a/src/geant4/Application.cpp
+++ b/src/geant4_application/src/Application.cpp
@@ -1,10 +1,10 @@
 
-#include "geant4/Application.h"
-#include "geant4/ActionInitialization.h"
-#include "geant4/DetectorConstruction.h"
-#include "geant4/PhysicsList.h"
-#include "geant4/RunAction.h"
-#include "geant4/SteppingVerbose.h"
+#include "geant4_application/Application.h"
+#include "geant4_application/ActionInitialization.h"
+#include "geant4_application/DetectorConstruction.h"
+#include "geant4_application/PhysicsList.h"
+#include "geant4_application/RunAction.h"
+#include "geant4_application/SteppingVerbose.h"
 
 // TODO: conditional include
 #include <G4UIExecutive.hh>
diff --git a/src/geant4/DataModel.cpp b/src/geant4_application/src/DataModel.cpp
similarity index 99%
rename from src/geant4/DataModel.cpp
rename to src/geant4_application/src/DataModel.cpp
index 96f3324..b5064c2 100644
--- a/src/geant4/DataModel.cpp
+++ b/src/geant4_application/src/DataModel.cpp
@@ -1,5 +1,5 @@
 
-#include "geant4/DataModel.h"
+#include "geant4_application/DataModel.h"
 
 #include <G4HadronicProcess.hh>
 #include <G4Nucleus.hh>
diff --git a/src/geant4/DetectorConstruction.cpp b/src/geant4_application/src/DetectorConstruction.cpp
similarity index 96%
rename from src/geant4/DetectorConstruction.cpp
rename to src/geant4_application/src/DetectorConstruction.cpp
index a698361..7c4e9b7 100644
--- a/src/geant4/DetectorConstruction.cpp
+++ b/src/geant4_application/src/DetectorConstruction.cpp
@@ -1,7 +1,7 @@
 #include <utility>
 
-#include "geant4/DetectorConstruction.h"
-#include "geant4/SensitiveDetector.h"
+#include "geant4_application/DetectorConstruction.h"
+#include "geant4_application/SensitiveDetector.h"
 
 #include <G4LogicalVolume.hh>
 #include <G4LogicalVolumeStore.hh>
diff --git a/src/geant4/EventAction.cpp b/src/geant4_application/src/EventAction.cpp
similarity index 76%
rename from src/geant4/EventAction.cpp
rename to src/geant4_application/src/EventAction.cpp
index cb80080..c821043 100644
--- a/src/geant4/EventAction.cpp
+++ b/src/geant4_application/src/EventAction.cpp
@@ -1,7 +1,7 @@
 
-#include "geant4/EventAction.h"
-#include "geant4/DataModel.h"
-#include "geant4/RunAction.h"
+#include "geant4_application/EventAction.h"
+#include "geant4_application/DataModel.h"
+#include "geant4_application/RunAction.h"
 
 #include <iostream>
 
diff --git a/src/geant4/PhysicsList.cpp b/src/geant4_application/src/PhysicsList.cpp
similarity index 96%
rename from src/geant4/PhysicsList.cpp
rename to src/geant4_application/src/PhysicsList.cpp
index fd7742f..90b4ab1 100644
--- a/src/geant4/PhysicsList.cpp
+++ b/src/geant4_application/src/PhysicsList.cpp
@@ -1,5 +1,5 @@
 
-#include "geant4/PhysicsList.h"
+#include "geant4_application/PhysicsList.h"
 
 #include <G4DecayPhysics.hh>
 #include <G4EmExtraPhysics.hh>
diff --git a/src/geant4/PrimaryGeneratorAction.cpp b/src/geant4_application/src/PrimaryGeneratorAction.cpp
similarity index 94%
rename from src/geant4/PrimaryGeneratorAction.cpp
rename to src/geant4_application/src/PrimaryGeneratorAction.cpp
index 9c5b2e9..eb155ff 100644
--- a/src/geant4/PrimaryGeneratorAction.cpp
+++ b/src/geant4_application/src/PrimaryGeneratorAction.cpp
@@ -1,6 +1,6 @@
 
-#include "geant4/PrimaryGeneratorAction.h"
-#include "geant4/Application.h"
+#include "geant4_application/PrimaryGeneratorAction.h"
+#include "geant4_application/Application.h"
 
 #include <G4Event.hh>
 #include <G4ParticleDefinition.hh>
diff --git a/src/geant4/RunAction.cpp b/src/geant4_application/src/RunAction.cpp
similarity index 92%
rename from src/geant4/RunAction.cpp
rename to src/geant4_application/src/RunAction.cpp
index c7886a9..7783e68 100644
--- a/src/geant4/RunAction.cpp
+++ b/src/geant4_application/src/RunAction.cpp
@@ -1,6 +1,6 @@
 
-#include "geant4/RunAction.h"
-#include "geant4/SteppingVerbose.h"
+#include "geant4_application/RunAction.h"
+#include "geant4_application/SteppingVerbose.h"
 
 #include <iostream>
 
diff --git a/src/geant4/SensitiveDetector.cpp b/src/geant4_application/src/SensitiveDetector.cpp
similarity index 85%
rename from src/geant4/SensitiveDetector.cpp
rename to src/geant4_application/src/SensitiveDetector.cpp
index d4f8d0c..5774e39 100644
--- a/src/geant4/SensitiveDetector.cpp
+++ b/src/geant4_application/src/SensitiveDetector.cpp
@@ -1,5 +1,5 @@
 
-#include "geant4/SensitiveDetector.h"
+#include "geant4_application/SensitiveDetector.h"
 
 using namespace std;
 using namespace geant4_app;
diff --git a/src/geant4/StackingAction.cpp b/src/geant4_application/src/StackingAction.cpp
similarity index 96%
rename from src/geant4/StackingAction.cpp
rename to src/geant4_application/src/StackingAction.cpp
index c8a00d2..2f8ffe9 100644
--- a/src/geant4/StackingAction.cpp
+++ b/src/geant4_application/src/StackingAction.cpp
@@ -1,5 +1,5 @@
 
-#include "geant4/StackingAction.h"
+#include "geant4_application/StackingAction.h"
 
 #include <G4ParticlePropertyTable.hh>
 #include <G4Track.hh>
diff --git a/src/geant4/SteppingAction.cpp b/src/geant4_application/src/SteppingAction.cpp
similarity index 67%
rename from src/geant4/SteppingAction.cpp
rename to src/geant4_application/src/SteppingAction.cpp
index aa21332..0feafe3 100644
--- a/src/geant4/SteppingAction.cpp
+++ b/src/geant4_application/src/SteppingAction.cpp
@@ -1,8 +1,8 @@
 
-#include "geant4/SteppingAction.h"
+#include "geant4_application/SteppingAction.h"
 
-#include "geant4/DataModel.h"
-#include "geant4/RunAction.h"
+#include "geant4_application/DataModel.h"
+#include "geant4_application/RunAction.h"
 #include <G4Step.hh>
 #include <iostream>
 
diff --git a/src/geant4/SteppingVerbose.cpp b/src/geant4_application/src/SteppingVerbose.cpp
similarity index 83%
rename from src/geant4/SteppingVerbose.cpp
rename to src/geant4_application/src/SteppingVerbose.cpp
index 868d30d..11dc769 100644
--- a/src/geant4/SteppingVerbose.cpp
+++ b/src/geant4_application/src/SteppingVerbose.cpp
@@ -1,7 +1,7 @@
 
-#include "geant4/SteppingVerbose.h"
-#include "geant4/DataModel.h"
-#include "geant4/RunAction.h"
+#include "geant4_application/SteppingVerbose.h"
+#include "geant4_application/DataModel.h"
+#include "geant4_application/RunAction.h"
 
 #include <iostream>
 
diff --git a/src/geant4/TrackingAction.cpp b/src/geant4_application/src/TrackingAction.cpp
similarity index 87%
rename from src/geant4/TrackingAction.cpp
rename to src/geant4_application/src/TrackingAction.cpp
index 2b010aa..b6832db 100644
--- a/src/geant4/TrackingAction.cpp
+++ b/src/geant4_application/src/TrackingAction.cpp
@@ -1,6 +1,6 @@
 
-#include "geant4/TrackingAction.h"
-#include "geant4/RunAction.h"
+#include "geant4_application/TrackingAction.h"
+#include "geant4_application/RunAction.h"
 
 #include <G4ParticleDefinition.hh>
 #include <G4ParticleTypes.hh>
diff --git a/src/python/module.cpp b/src/python/module.cpp
index d3da17f..3f00df9 100644
--- a/src/python/module.cpp
+++ b/src/python/module.cpp
@@ -1,7 +1,7 @@
 
 #include <pybind11/pybind11.h>
 
-#include "geant4/Application.h"
+#include "geant4_application/Application.h"
 
 #define STRINGIFY(x) #x
 #define MACRO_STRINGIFY(x) STRINGIFY(x)