diff --git a/server/src/main/java/org/opensearch/identity/noop/NoopPluginSubject.java b/server/src/main/java/org/opensearch/identity/noop/NoopPluginSubject.java
index b266bc9620def..e06711e8cec19 100644
--- a/server/src/main/java/org/opensearch/identity/noop/NoopPluginSubject.java
+++ b/server/src/main/java/org/opensearch/identity/noop/NoopPluginSubject.java
@@ -18,7 +18,7 @@
 import java.util.concurrent.Callable;
 
 public class NoopPluginSubject extends AbstractSubject {
-    private ThreadPool threadPool;
+    private final ThreadPool threadPool;
 
     public NoopPluginSubject(ThreadPool threadPool) {
         super();