diff --git a/src/machine_learning/nearest_neighbour/CrossValidation.java b/src/machine_learning/nearest_neighbour/CrossValidation.java
index f19f4d6..8087217 100644
--- a/src/machine_learning/nearest_neighbour/CrossValidation.java
+++ b/src/machine_learning/nearest_neighbour/CrossValidation.java
@@ -12,8 +12,8 @@ import java.util.stream.IntStream;
 
 public class CrossValidation
 {
-    private int paramMin;
-    private int paramMax;
+    private final int paramMin;
+    private final int paramMax;
 
     public CrossValidation(int paramMin, int paramMax)
     {
diff --git a/src/machine_learning/nearest_neighbour/KNearestNeighbour.java b/src/machine_learning/nearest_neighbour/KNearestNeighbour.java
index 2dea8c7..6e63038 100644
--- a/src/machine_learning/nearest_neighbour/KNearestNeighbour.java
+++ b/src/machine_learning/nearest_neighbour/KNearestNeighbour.java
@@ -15,9 +15,9 @@ public class KNearestNeighbour implements MachineLearning
     private List<Vector> positives;
     private List<Vector> negatives;
 
-    private Distance distance;
+    private final Distance distance;
 
-    private int k;
+    private final int k;
 
     public KNearestNeighbour(Distance distance)
     {