diff --git a/MuonSpectrometer/MuonSimData/MuonSimData/CscSimData.h b/MuonSpectrometer/MuonSimData/MuonSimData/CscSimData.h
index cfa1edf63f67f9d0357d2d030247514ed62a821e..9853ab51b30e67e1bfd41fb67874564aca956fbd 100644
--- a/MuonSpectrometer/MuonSimData/MuonSimData/CscSimData.h
+++ b/MuonSpectrometer/MuonSimData/MuonSimData/CscSimData.h
@@ -65,6 +65,7 @@ public:
 private:
   int m_word;  
   std::vector<Deposit> m_deposits;
+  CscSimData & operator=(const CscSimData &right);
 };
 
 //<<<<<< INLINE PUBLIC FUNCTIONS                                        >>>>>>
diff --git a/MuonSpectrometer/MuonSimData/MuonSimData/MuonSimData.h b/MuonSpectrometer/MuonSimData/MuonSimData/MuonSimData.h
index 42ce16cb8c922440cdfefefda571b1a39d20e444..58d3ee04662268653fdd0bf81ba8202a7f8dc2f1 100644
--- a/MuonSpectrometer/MuonSimData/MuonSimData/MuonSimData.h
+++ b/MuonSpectrometer/MuonSimData/MuonSimData/MuonSimData.h
@@ -87,6 +87,7 @@ private:
     float x;
     float y;
     float z;
+    MuonSimData & operator=(const MuonSimData &right);
 };
 
 //<<<<<< INLINE PUBLIC FUNCTIONS                                        >>>>>>