diff --git a/DDG4/lcio/LCIOFileReader.cpp b/DDG4/lcio/LCIOFileReader.cpp
index eb50d05ab6d6bb995850df36a7067e0031bf8130..d75dbb154ca731a64878b94d3b903d719b223c10 100644
--- a/DDG4/lcio/LCIOFileReader.cpp
+++ b/DDG4/lcio/LCIOFileReader.cpp
@@ -97,7 +97,7 @@ DD4hep::Simulation::LCIOFileReader::moveToEvent(int event_number) {
 
 /// Read an event and fill a vector of MCParticles.
 Geant4EventReader::EventReaderStatus
-DD4hep::Simulation::LCIOFileReader::readParticleCollection(int event_number, EVENT::LCCollection** particles)  {
+DD4hep::Simulation::LCIOFileReader::readParticleCollection(int /*event_number*/, EVENT::LCCollection** particles)  {
 
   ::lcio::LCEvent* evt = m_reader->readNextEvent(); // simply read the events sequentially 
   ++m_currEvent ;
diff --git a/DDG4/lcio/LCIOStdHepReader.cpp b/DDG4/lcio/LCIOStdHepReader.cpp
index 1a04cd3826ed1666b0e65ecd7073db2e4bbe7e6b..d929de5d258c3ba3a80b9d846f7fda90c561d381 100644
--- a/DDG4/lcio/LCIOStdHepReader.cpp
+++ b/DDG4/lcio/LCIOStdHepReader.cpp
@@ -104,7 +104,7 @@ LCIOStdHepReader::moveToEvent(int event_number) {
 
 /// Read an event and fill a vector of MCParticles.
 Geant4EventReader::EventReaderStatus
-LCIOStdHepReader::readParticleCollection(int event_number, EVENT::LCCollection** particles)  {
+LCIOStdHepReader::readParticleCollection(int /*event_number*/, EVENT::LCCollection** particles)  {
 
   *particles = m_reader->readEvent();
   ++m_currEvent;