diff --git a/DDG4/lcio/LCIOSDTestActions.cpp b/DDG4/lcio/LCIOSDTestActions.cpp
index 3e7d4e02664c3f41229a2c123e93964856ec6598..6bbbbd16927c2cddadb14e54471948f0581700dc 100644
--- a/DDG4/lcio/LCIOSDTestActions.cpp
+++ b/DDG4/lcio/LCIOSDTestActions.cpp
@@ -147,7 +147,7 @@ namespace  Tests {
   }
 
   /// Method for generating hit(s) using the information of G4Step object.
-  template <> bool Geant4SensitiveAction<LcioTestTracker>::process(Geant4FastSimSpot* ,G4TouchableHistory* /*hist*/ ) {
+  template <> bool Geant4SensitiveAction<LcioTestTracker>::process(const Geant4FastSimSpot* ,G4TouchableHistory* /*hist*/ ) {
     except("Not implemented");
     return true;
   }