diff --git a/trunk/paradiseo-moeo/src/core/MOEO.h b/trunk/paradiseo-moeo/src/core/MOEO.h
index b718c38ef..44b83c07c 100644
--- a/trunk/paradiseo-moeo/src/core/MOEO.h
+++ b/trunk/paradiseo-moeo/src/core/MOEO.h
@@ -345,7 +345,7 @@ class MOEO : public EO < MOEOObjectiveVector >
      * Getter for "flag"
      * @return the flag value
      */
-    int flag(){
+    int flag() const{
     	return flagValue;
     }