Fix reference to _g4chroma module

1 files changed, 3 insertions, 3 deletions

diff --git a/chroma/generator/g4gen.py b/chroma/generator/g4gen.py
index fa4521d..7f55e56 100644
--- a/chroma/generator/g4gen.py
+++ b/chroma/generator/g4gen.py
@@ -5,7 +5,7 @@ import g4py.ParticleGun
 import pyublas
 import numpy as np
 from chroma.event import Photons, Vertex
-import chroma.generator._g4chroma
+from chroma.generator import _g4chroma
 
 class G4Generator(object):
     def __init__(self, material, seed=None):
@@ -26,7 +26,7 @@ class G4Generator(object):
 
         g4py.NISTmaterials.Construct()
         g4py.ezgeom.Construct()
-        self.physics_list = G4chroma.ChromaPhysicsList()
+        self.physics_list = _g4chroma.ChromaPhysicsList()
         gRunManager.SetUserInitialization(self.physics_list)
         self.particle_gun = g4py.ParticleGun.Construct()
         
@@ -38,7 +38,7 @@ class G4Generator(object):
         self.world.CreateBoxVolume(self.world_material, 100*m, 100*m, 100*m)
         self.world.PlaceIt(G4ThreeVector(0,0,0))
 
-        self.tracking_action = G4chroma.PhotonTrackingAction()
+        self.tracking_action = _g4chroma.PhotonTrackingAction()
         gRunManager.SetUserAction(self.tracking_action)
         gRunManager.Initialize()