diff --git a/GNUmakefile b/GNUmakefile
index 010aa7d..7291e0f 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -45,6 +45,7 @@ CPPFLAGS += -DG4MULTITHREADED
 #CPPFLAGS += -DDEBUG_PLACEMENT
 #CPPFLAGS += -DDEBUG_SECTIONPLANE
 #CPPFLAGS += -DDEBUG_SECTIONPLANE_ZAVE
+#CPPFLAGS += -DG4VERSION_10_04_OR_LATER=1
 
 # If you want to build against Geant4.10.03 or greater, you will need this line uncommented
 #CPPFLAGS += -DG4VUSERPHYSICSLIST_HAS_GETPARTICLEITERATOR
diff --git a/src/GlueXDetectorConstruction.cc b/src/GlueXDetectorConstruction.cc
index aa40002..9648026 100644
--- a/src/GlueXDetectorConstruction.cc
+++ b/src/GlueXDetectorConstruction.cc
@@ -446,8 +446,13 @@ void GlueXDetectorConstruction::CloneF()
             // First time we see this FM, let's clone and remember...
 
             G4ChordFinder *cfinder = masterFM->GetChordFinder();
+#if G4VERSION_10_04_OR_LATER
+            G4VIntegrationDriver *midriver = cfinder->GetIntegrationDriver();
+            double stepMinimum = 1e-2;
+#else
             G4MagInt_Driver *midriver = cfinder->GetIntegrationDriver();
             double stepMinimum = midriver->GetHmin();
+#endif
             G4MagIntegratorStepper *stepper = midriver->GetStepper();
             const G4Field *field = masterFM->GetDetectorField();
 
diff --git a/src/GlueXPhysicsList.hh b/src/GlueXPhysicsList.hh
index c259d79..b2ef805 100644
--- a/src/GlueXPhysicsList.hh
+++ b/src/GlueXPhysicsList.hh
@@ -59,7 +59,7 @@ class GlueXPhysicsList: public G4VModularPhysicsList
 #endif
    G4OpticalPhysics *fOpticalPhysics;
 
-#ifndef G4VUSERPHYSICSLIST_HAS_GETPARTICLEITERATOR
+#ifndef G4VERSION_10_04_OR_LATER
    // This member function gets introduced into base class
    // G4VUserPhysicsList in release Geant4.10.03, but until
    // we abandon ability to build under previous releases,