diff --git a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/CounterUnitTest.java b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/CounterUnitTest.java
index 6761b05282..d8f8ff2b7d 100644
--- a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/CounterUnitTest.java
+++ b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/CounterUnitTest.java
@@ -18,8 +18,11 @@ public class CounterUnitTest {
         Counter counter = new Counter();
         Future<Integer> future1 = (Future<Integer>) executorService.submit(new CounterCallable(counter));
         Future<Integer> future2 = (Future<Integer>) executorService.submit(new CounterCallable(counter));
-        
-        assertThat(future1.get()).isEqualTo(1);
-        assertThat(future2.get()).isEqualTo(2);
+
+        // Just to make sure both are completed
+        future1.get();
+        future2.get();
+
+        assertThat(counter.getCounter()).isEqualTo(2);
     }
 }
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/ExtrinsicLockCounterUnitTest.java
index 2dcb846bf4..0fc3dd3a54 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/ExtrinsicLockCounterUnitTest.java
@@ -18,8 +18,11 @@ public class ExtrinsicLockCounterUnitTest {
         ExtrinsicLockCounter counter = new ExtrinsicLockCounter();
         Future<Integer> future1 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(counter));
         Future<Integer> future2 = (Future<Integer>) executorService.submit(new ExtrinsicLockCounterCallable(counter));
-        
-        assertThat(future1.get()).isEqualTo(1);
-        assertThat(future2.get()).isEqualTo(2);
+
+        // Just to make sure both are completed
+        future1.get();
+        future2.get();
+
+        assertThat(counter.getCounter()).isEqualTo(2);
     }
 }
diff --git a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantLockCounterUnitTest.java b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantLockCounterUnitTest.java
index 330d2d4c86..9932aa9bbc 100644
--- a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantLockCounterUnitTest.java
+++ b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantLockCounterUnitTest.java
@@ -11,15 +11,18 @@ import java.util.concurrent.Future;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class ReentrantLockCounterUnitTest {
-    
+
     @Test
     public void whenCalledIncrementCounter_thenCorrect() throws Exception {
         ExecutorService executorService = Executors.newFixedThreadPool(2);
         ReentrantLockCounter counter = new ReentrantLockCounter();
         Future<Integer> future1 = (Future<Integer>) executorService.submit(new ReentrantLockCounterCallable(counter));
         Future<Integer> future2 = (Future<Integer>) executorService.submit(new ReentrantLockCounterCallable(counter));
-        
-        assertThat(future1.get()).isEqualTo(1);
-        assertThat(future2.get()).isEqualTo(2);
+
+        // Just to make sure both are completed
+        future1.get();
+        future2.get();
+
+        assertThat(counter.getCounter()).isEqualTo(2);
     }
 }
diff --git a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantReadWriteLockCounterUnitTest.java b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantReadWriteLockCounterUnitTest.java
index 71fad2c87f..c82cd39074 100644
--- a/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantReadWriteLockCounterUnitTest.java
+++ b/core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/threadsafety/ReentrantReadWriteLockCounterUnitTest.java
@@ -11,16 +11,19 @@ import java.util.concurrent.Future;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class ReentrantReadWriteLockCounterUnitTest {
-    
+
     @Test
     public void whenCalledIncrementCounter_thenCorrect() throws Exception {
         ExecutorService executorService = Executors.newFixedThreadPool(2);
         ReentrantReadWriteLockCounter counter = new ReentrantReadWriteLockCounter();
-        Future<Integer> future1 = (Future<Integer>) executorService.submit(new  ReentranReadWriteLockCounterCallable(counter));
-        Future<Integer> future2 = (Future<Integer>) executorService.submit(new  ReentranReadWriteLockCounterCallable(counter));
+        Future<Integer> future1 = (Future<Integer>) executorService.submit(new ReentranReadWriteLockCounterCallable(counter));
+        Future<Integer> future2 = (Future<Integer>) executorService.submit(new ReentranReadWriteLockCounterCallable(counter));
 
-        assertThat(future2.get()).isEqualTo(2);
-        assertThat(future1.get()).isEqualTo(1);
+        // Just to make sure both are completed
+        future1.get();
+        future2.get();
+
+        assertThat(counter.getCounter()).isEqualTo(2);
     }
-    
+
 }