diff --git a/graf2d/graf/inc/TSpline.h b/graf2d/graf/inc/TSpline.h
index c9e014187c3b2d687401fe3eabb834afdd678812..3e492afacb92248849890d0687a10d7cf3fff642 100644
--- a/graf2d/graf/inc/TSpline.h
+++ b/graf2d/graf/inc/TSpline.h
@@ -94,7 +94,7 @@ public:
 
 inline TSplinePoly::TSplinePoly(TSplinePoly const &other)
 :
-  TObject(other)
+   TObject(other), fX(0), fY(0)
 {
   CopyPoly(other);
 }
@@ -136,7 +136,7 @@ private:
 
 inline TSplinePoly3::TSplinePoly3(TSplinePoly3 const &other)
 :
-  TSplinePoly(other)
+		    TSplinePoly(other), fB(0), fC(0), fD(0)
 {
   CopyPoly(other);
 }
@@ -182,7 +182,7 @@ private:
 
 inline TSplinePoly5::TSplinePoly5(TSplinePoly5 const &other)
 :
-  TSplinePoly(other)
+    TSplinePoly(other), fB(0), fC(0), fD(0), fE(0), fF(0)
 {
   CopyPoly(other);
 }
diff --git a/io/io/inc/TArchiveFile.h b/io/io/inc/TArchiveFile.h
index 4c5b559262a3484a06422e13996667a9b2443e93..46220a8a9f3c89a6e44508460c04217f87cee210 100644
--- a/io/io/inc/TArchiveFile.h
+++ b/io/io/inc/TArchiveFile.h
@@ -40,6 +40,10 @@ class TObjArray;
 class TArchiveFile : public TObject {
 
 protected:
+
+   TArchiveFile(const TArchiveFile&); // Not implemented
+   TArchiveFile& operator=(const TArchiveFile&); // Not implemented
+
    TString         fArchiveName;  // Archive file name
    TString         fMemberName;   // Sub-file name
    Int_t           fMemberIndex;  // Index of sub-file in archive
diff --git a/proof/proof/inc/TProof.h b/proof/proof/inc/TProof.h
index 6c48a2721f82cca5ab624ee905cfeebe4797946e..3898ef21f36add83fea1d165fbdfd2563e967405 100644
--- a/proof/proof/inc/TProof.h
+++ b/proof/proof/inc/TProof.h
@@ -171,6 +171,12 @@ public:
                    TList *s, TProof *prf);
 
    virtual ~TProofThreadArg() { if (fUrl) delete fUrl; }
+
+private:
+
+   TProofThreadArg(const TProofThreadArg&); // Not implemented
+   TProofThreadArg& operator=(const TProofThreadArg&); // Not implemented
+
 };
 
 // PROOF Thread class for parallel startup
@@ -179,13 +185,22 @@ public:
    TThread         *fThread;
    TProofThreadArg *fArgs;
 
-   TProofThread(TThread *t, TProofThreadArg *a) { fThread = t; fArgs = a; }
+   TProofThread(TThread *t, TProofThreadArg *a) : fThread(t), fArgs(a) {}
    virtual ~TProofThread() { SafeDelete(fThread); SafeDelete(fArgs); }
+private:
+
+   TProofThread(const TProofThread&); // Not implemented
+   TProofThread& operator=(const TProofThread&); // Not implemented
+
 };
 
 // PROOF Interrupt signal handler
 class TProofInterruptHandler : public TSignalHandler {
 private:
+
+   TProofInterruptHandler(const TProofInterruptHandler&); // Not implemented
+   TProofInterruptHandler& operator=(const TProofInterruptHandler&); // Not implemented
+
    TProof *fProof;
 public:
    TProofInterruptHandler(TProof *p)
@@ -196,6 +211,10 @@ public:
 // Input handler for messages from TProofServ
 class TProofInputHandler : public TFileHandler {
 private:
+
+   TProofInputHandler(const TProofInputHandler&); // Not implemented
+   TProofInputHandler& operator=(const TProofInputHandler&); // Not implemented
+
    TSocket *fSocket;
    TProof  *fProof;
 public: