diff --git a/bind/bindings.cpp b/bind/bindings.cpp
index 4d85c29..722a6fb 100644
--- a/bind/bindings.cpp
+++ b/bind/bindings.cpp
@@ -21,7 +21,7 @@ void makeSystemBuilder(M& m, std::string name){
     py::class_<SystemBuilder>(m, name.data()).def(py::init())
     .def("init", &SystemBuilder::init, py::arg("cw"), py::arg("gui")=false)
     .def("run_gui", &SystemBuilder::run_gui)
-    .def("run_batch", &SystemBuilder::run_batch)
+    .def("run_batch", &SystemBuilder::run_batch, py::arg("nEvents"), py::arg("partSpecies"), py::arg("minEnergy"), py::arg("maxEnergy"))
     .def("visualize", &SystemBuilder::visualize);
 }
 
diff --git a/src/SystemBuilder.cc b/src/SystemBuilder.cc
index 4814791..da38919 100644
--- a/src/SystemBuilder.cc
+++ b/src/SystemBuilder.cc
@@ -60,6 +60,8 @@ void SystemBuilder::run_gui(){
 }
 
 void SystemBuilder::run_batch(int nEvents, std::string partSpecies, double minEnergy, double maxEnergy){
+    G4String partSpec = (G4String)partSpecies;
+    G4cout << "running with particle species " << partSpec << G4endl;
     actionInitialization->setGeneratorProperties(minEnergy, maxEnergy, (G4String)partSpecies);
     UImanager->ApplyCommand("/run/initialize");
     runManager->BeamOn(nEvents);