diff --git a/trunk/paradiseo-mo/src/neighborhood/moIndexNeighborhood.h b/trunk/paradiseo-mo/src/neighborhood/moIndexNeighborhood.h
index 1b7097e38..83d06b267 100644
--- a/trunk/paradiseo-mo/src/neighborhood/moIndexNeighborhood.h
+++ b/trunk/paradiseo-mo/src/neighborhood/moIndexNeighborhood.h
@@ -60,7 +60,7 @@ public:
 	 * getter to get the value of neighborhoodSize
 	 * @return the neighborhoodSize
 	 */
-	unsigned int getNeighborhoodSize() {
+	unsigned int getNeighborhoodSize() const {
 		return neighborhoodSize;
 	}