diff --git a/src/search/EightPuzzleNode.java b/src/search/EightPuzzleNode.java
index 3581c04..47712b5 100644
--- a/src/search/EightPuzzleNode.java
+++ b/src/search/EightPuzzleNode.java
@@ -12,11 +12,6 @@ public class EightPuzzleNode extends Node<int[][]>
         super(state);
     }
 
-    private EightPuzzleNode(final int[][] value, final Node<int[][]> parent)
-    {
-        super(value, parent);
-    }
-
     private EightPuzzleNode(final int[][] value, final Node<int[][]> parent, final int heuristicCosts)
     {
         super(value, parent, heuristicCosts);
diff --git a/src/search/Node.java b/src/search/Node.java
index a017c88..0d7d3f8 100644
--- a/src/search/Node.java
+++ b/src/search/Node.java
@@ -6,7 +6,7 @@ import java.util.Objects;
 public abstract class Node<T>
 {
     protected final T value;
-    protected int heuristicCosts;
+    protected final int heuristicCosts;
     private final Node<T> parent;
     private int heuristicEstimation;