diff --git a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/application/Application.java b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/application/Application.java
index 5fcb28cd2a..ebd027ea68 100644
--- a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/application/Application.java
+++ b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/application/Application.java
@@ -9,7 +9,7 @@ import com.baeldung.concurrent.threadsafety.callables.ReentranReadWriteLockCount
 import com.baeldung.concurrent.threadsafety.callables.ReentrantLockCounterCallable;
 import com.baeldung.concurrent.threadsafety.services.AtomicCounter;
 import com.baeldung.concurrent.threadsafety.services.Counter;
-import com.baeldung.concurrent.threadsafety.services.ExtrinsicLockCounter;
+import com.baeldung.concurrent.threadsafety.services.ObjectLockCounter;
 import com.baeldung.concurrent.threadsafety.services.MessageService;
 import com.baeldung.concurrent.threadsafety.services.ReentrantLockCounter;
 import com.baeldung.concurrent.threadsafety.services.ReentrantReadWriteLockCounter;
@@ -48,9 +48,9 @@ public class Application {
         System.out.println(future3.get());
         System.out.println(future4.get());
         
-        ExtrinsicLockCounter extrinsicLockCounter = new ExtrinsicLockCounter();
-        Future<Integer> future5 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(extrinsicLockCounter));
-        Future<Integer> future6 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(extrinsicLockCounter));
+        ObjectLockCounter objectLockCounter = new ObjectLockCounter();
+        Future<Integer> future5 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(objectLockCounter));
+        Future<Integer> future6 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(objectLockCounter));
         System.out.println(future5.get());
         System.out.println(future6.get());
         
diff --git a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/callables/ExtrinsicLockCounterCallable.java b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/callables/ExtrinsicLockCounterCallable.java
index 370e5d1f00..dcc929d3c4 100644
--- a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/callables/ExtrinsicLockCounterCallable.java
+++ b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/callables/ExtrinsicLockCounterCallable.java
@@ -1,13 +1,13 @@
 package com.baeldung.concurrent.threadsafety.callables;
 
-import com.baeldung.concurrent.threadsafety.services.ExtrinsicLockCounter;
+import com.baeldung.concurrent.threadsafety.services.ObjectLockCounter;
 import java.util.concurrent.Callable;
 
 public class ExtrinsicLockCounterCallable implements Callable<Integer> {
 
-    private final ExtrinsicLockCounter counter;
+    private final ObjectLockCounter counter;
     
-    public ExtrinsicLockCounterCallable(ExtrinsicLockCounter counter) {
+    public ExtrinsicLockCounterCallable(ObjectLockCounter counter) {
         this.counter = counter;
     }
     
diff --git a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ExtrinsicLockCounter.java b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ObjectLockCounter.java
similarity index 84%
rename from core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ExtrinsicLockCounter.java
rename to core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ObjectLockCounter.java
index 0a6ff3f60e..f31cf899ba 100644
--- a/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ExtrinsicLockCounter.java
+++ b/core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/threadsafety/services/ObjectLockCounter.java
@@ -1,11 +1,11 @@
 package com.baeldung.concurrent.threadsafety.services;
 
-public class ExtrinsicLockCounter {
+public class ObjectLockCounter {
 
     private int counter;
     private final Object lock = new Object();
 
-    public ExtrinsicLockCounter() {
+    public ObjectLockCounter() {
         this.counter = 0;
     }
 
diff --git a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ExtrinsicLockCounterUnitTest.java b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ObjectLockCounterUnitTest.java
similarity index 82%
rename from core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ExtrinsicLockCounterUnitTest.java
rename to core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ObjectLockCounterUnitTest.java
index 0fc3dd3a54..b0ac80a3aa 100644
--- a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ExtrinsicLockCounterUnitTest.java
+++ b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ObjectLockCounterUnitTest.java
@@ -1,7 +1,7 @@
 package com.baeldung.concurrent.threadsafety;
 
 import com.baeldung.concurrent.threadsafety.callables.ExtrinsicLockCounterCallable;
-import com.baeldung.concurrent.threadsafety.services.ExtrinsicLockCounter;
+import com.baeldung.concurrent.threadsafety.services.ObjectLockCounter;
 import org.junit.Test;
 
 import java.util.concurrent.ExecutorService;
@@ -10,12 +10,12 @@ import java.util.concurrent.Future;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-public class ExtrinsicLockCounterUnitTest {
+public class ObjectLockCounterUnitTest {
 
     @Test
     public void whenCalledIncrementCounter_thenCorrect() throws Exception {
         ExecutorService executorService = Executors.newFixedThreadPool(2);
-        ExtrinsicLockCounter counter = new ExtrinsicLockCounter();
+        ObjectLockCounter counter = new ObjectLockCounter();
         Future<Integer> future1 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(counter));
         Future<Integer> future2 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(counter));