diff --git a/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/UnifiedDistanceMatrix.java b/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/UnifiedDistanceMatrix.java
index 1445f55a8..7e6af35c4 100644
--- a/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/UnifiedDistanceMatrix.java
+++ b/src/main/java/org/apache/commons/math4/ml/neuralnet/twod/util/UnifiedDistanceMatrix.java
@@ -60,6 +60,7 @@ public class UnifiedDistanceMatrix implements MapVisualization {
     }
 
     /** {@inheritDoc} */
+    @Override
     public double[][] computeImage(NeuronSquareMesh2D map) {
         if (individualDistances) {
             return individualDistances(map);