diff --git a/trunk/paradiseo-moeo/src/core/MOEO.h b/trunk/paradiseo-moeo/src/core/MOEO.h
index 785cd6bf5..8b03c1bab 100644
--- a/trunk/paradiseo-moeo/src/core/MOEO.h
+++ b/trunk/paradiseo-moeo/src/core/MOEO.h
@@ -325,11 +325,11 @@ class MOEO : public EO < MOEOObjectiveVector >
       {
         if ( invalidObjectiveVector() )
           {
-            _os << "INVALID\t";
+            _os << "INVALID ";
           }
         else
           {
-            _os << objectiveVectorValue << '\t';
+            _os << objectiveVectorValue << ' ';
           }
       }