diff --git a/DDG4/src/Geant4SensDetAction.cpp b/DDG4/src/Geant4SensDetAction.cpp
index abf808a1873f23c43482576be75e92a713b3c67f..b8136abbd2caae74cdd334e2a7325fda83547d22 100644
--- a/DDG4/src/Geant4SensDetAction.cpp
+++ b/DDG4/src/Geant4SensDetAction.cpp
@@ -202,8 +202,9 @@ long long int Geant4Sensitive::cellID(G4Step* s) {
   if ( m_segmentation.isValid() )  {
     G4ThreeVector global = 0.5 * ( h.prePosG4()+h.postPosG4());
     G4ThreeVector local  = h.preTouchable()->GetHistory()->GetTopTransform().TransformPoint(global);
-    Position loc(local.x(), local.y(), local.z()), glob(global.x(), global.y(), global.z());
-    VolumeID cellID      = m_segmentation.cellID(loc,glob,volID);
+    Position loc(local.x()*MM_2_CM, local.y()*MM_2_CM, local.z()*MM_2_CM);
+    Position glob(global.x()*MM_2_CM, global.y()*MM_2_CM, global.z()*MM_2_CM);
+    VolumeID cellID = m_segmentation.cellID(loc,glob,volID);
     return cellID;
   }
   return volID;