diff --git a/eo/src/eoInitializer.h b/eo/src/eoInitializer.h
index 506fcf73..9e5cd5ca 100644
--- a/eo/src/eoInitializer.h
+++ b/eo/src/eoInitializer.h
@@ -129,7 +129,7 @@ private :
 class eoDummyEval : public eoPopEvalFunc<POT>
     {
     public:
-        void operator()(eoPop<POT> &,eoPop<POT> &_pop)
+        void operator()(eoPop<POT> &,eoPop<POT> &/*_pop*/)
         {}
     }
     dummyEval;
diff --git a/eo/src/eoPeriodicContinue.h b/eo/src/eoPeriodicContinue.h
index a6f968e9..1a3f9d0d 100644
--- a/eo/src/eoPeriodicContinue.h
+++ b/eo/src/eoPeriodicContinue.h
@@ -39,7 +39,7 @@ public:
 
   /** It returns 'true' only if the current number of generations modulo
       the period doen't equal to zero. */
-  bool operator () (const eoPop <EOT> & pop)
+  bool operator () (const eoPop <EOT> & /*pop*/)
   {
     return ((++ counter) % period) != 0 ;
   }
diff --git a/eo/src/eoProportionalSelect.h b/eo/src/eoProportionalSelect.h
index daa4428d..ec1243ce 100644
--- a/eo/src/eoProportionalSelect.h
+++ b/eo/src/eoProportionalSelect.h
@@ -46,7 +46,7 @@ template <class EOT> class eoProportionalSelect: public eoSelectOne<EOT>
 {
 public:
   /// Sanity check
-  eoProportionalSelect(const eoPop<EOT>& pop = eoPop<EOT>())
+  eoProportionalSelect(const eoPop<EOT>& /*pop*/ = eoPop<EOT>())
   {
     if (minimizing_fitness<EOT>())
       throw std::logic_error("eoProportionalSelect: minimizing fitness");
diff --git a/eo/src/eoSyncEasyPSO.h b/eo/src/eoSyncEasyPSO.h
index f05f15f6..a3b4f36e 100644
--- a/eo/src/eoSyncEasyPSO.h
+++ b/eo/src/eoSyncEasyPSO.h
@@ -241,7 +241,7 @@ private:
         {
                 public:
         eoDummyFlight () {}
-        void operator  () (POT & _po) {}
+	void operator  () (POT & /*_po*/) {}
         }dummyFlight;
 
         // if the initializer does not need to be used, use the dummy one instead
diff --git a/eo/src/eoVelocity.h b/eo/src/eoVelocity.h
index 753c6af2..5bbdb7c5 100644
--- a/eo/src/eoVelocity.h
+++ b/eo/src/eoVelocity.h
@@ -57,7 +57,7 @@ public:
     /**
      * Update the neighborhood of the given particle.
      */
-    virtual void updateNeighborhood(POT & ,unsigned _indice){}
+    virtual void updateNeighborhood(POT & ,unsigned /*_indice*/){}
 
 
     /**