diff --git a/src/backend/history.hh b/src/backend/history.hh
index 8c6a6b9..62e5637 100644
--- a/src/backend/history.hh
+++ b/src/backend/history.hh
@@ -89,6 +89,8 @@ namespace sgpem
 		
   protected:
 	History();			//private constructor.
+	History(const History&);
+	History& operator=(const History&);
 
   private:
 	int             _total_time_elapsed;
diff --git a/src/backend/policies_gatekeeper.hh b/src/backend/policies_gatekeeper.hh
index cd6d99d..33fb45b 100644
--- a/src/backend/policies_gatekeeper.hh
+++ b/src/backend/policies_gatekeeper.hh
@@ -62,6 +62,8 @@ namespace sgpem
     
   private:
     PoliciesGatekeeper();	    //private constructor.
+    PoliciesGatekeeper(const PoliciesGatekeeper&);
+    PoliciesGatekeeper& operator=(const PoliciesGatekeeper&);
     
     // Deactivates active policies managed by the specified manager.
     void			    deactivate_policies(PolicyManager* manager);