diff --git a/spring-context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java b/spring-context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java
index bdaa76e33e1..52e51818305 100644
--- a/spring-context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java
+++ b/spring-context/src/main/java/org/springframework/scheduling/concurrent/ConcurrentTaskScheduler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -177,6 +177,7 @@ public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements T
 	 * @see Clock#systemDefaultZone()
 	 */
 	public void setClock(Clock clock) {
+		Assert.notNull(clock, "Clock must not be null");
 		this.clock = clock;
 	}
 
diff --git a/spring-context/src/main/java/org/springframework/scheduling/concurrent/ThreadPoolTaskScheduler.java b/spring-context/src/main/java/org/springframework/scheduling/concurrent/ThreadPoolTaskScheduler.java
index ca9a0344ea6..1094d0ddd48 100644
--- a/spring-context/src/main/java/org/springframework/scheduling/concurrent/ThreadPoolTaskScheduler.java
+++ b/spring-context/src/main/java/org/springframework/scheduling/concurrent/ThreadPoolTaskScheduler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,8 +45,9 @@ import org.springframework.util.concurrent.ListenableFuture;
 import org.springframework.util.concurrent.ListenableFutureTask;
 
 /**
- * Implementation of Spring's {@link TaskScheduler} interface, wrapping
- * a native {@link java.util.concurrent.ScheduledThreadPoolExecutor}.
+ * A standard implementation of Spring's {@link TaskScheduler} interface, wrapping
+ * a native {@link java.util.concurrent.ScheduledThreadPoolExecutor} and providing
+ * all applicable configuration options for it.
  *
  * @author Juergen Hoeller
  * @author Mark Fisher
@@ -154,6 +155,7 @@ public class ThreadPoolTaskScheduler extends ExecutorConfigurationSupport
 	 * @see Clock#systemDefaultZone()
 	 */
 	public void setClock(Clock clock) {
+		Assert.notNull(clock, "Clock must not be null");
 		this.clock = clock;
 	}
 
diff --git a/spring-context/src/test/java/org/springframework/scheduling/concurrent/ConcurrentTaskExecutorTests.java b/spring-context/src/test/java/org/springframework/scheduling/concurrent/ConcurrentTaskExecutorTests.java
index 9cc17d75657..10f246757fb 100644
--- a/spring-context/src/test/java/org/springframework/scheduling/concurrent/ConcurrentTaskExecutorTests.java
+++ b/spring-context/src/test/java/org/springframework/scheduling/concurrent/ConcurrentTaskExecutorTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,8 +17,8 @@
 package org.springframework.scheduling.concurrent;
 
 import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
 import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.RunnableFuture;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
@@ -52,8 +52,8 @@ class ConcurrentTaskExecutorTests extends AbstractSchedulingTaskExecutorTests {
 	@AfterEach
 	void shutdownExecutor() {
 		for (Runnable task : concurrentExecutor.shutdownNow()) {
-			if (task instanceof RunnableFuture) {
-				((RunnableFuture<?>) task).cancel(true);
+			if (task instanceof Future) {
+				((Future<?>) task).cancel(true);
 			}
 		}
 	}
diff --git a/spring-context/src/test/java/org/springframework/scheduling/concurrent/ThreadPoolTaskSchedulerTests.java b/spring-context/src/test/java/org/springframework/scheduling/concurrent/ThreadPoolTaskSchedulerTests.java
index a9654464062..259ad775f14 100644
--- a/spring-context/src/test/java/org/springframework/scheduling/concurrent/ThreadPoolTaskSchedulerTests.java
+++ b/spring-context/src/test/java/org/springframework/scheduling/concurrent/ThreadPoolTaskSchedulerTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,7 +39,7 @@ import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
  * @author Sam Brannen
  * @since 3.0
  */
-public class ThreadPoolTaskSchedulerTests extends AbstractSchedulingTaskExecutorTests {
+class ThreadPoolTaskSchedulerTests extends AbstractSchedulingTaskExecutorTests {
 
 	private final ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
 
@@ -97,7 +97,7 @@ public class ThreadPoolTaskSchedulerTests extends AbstractSchedulingTaskExecutor
 	}
 
 	@Test
-	void scheduleOneTimeFailingTaskWithoutErrorHandler() throws Exception {
+	void scheduleOneTimeFailingTaskWithoutErrorHandler() {
 		TestTask task = new TestTask(this.testName, 0);
 		Future<?> future = scheduler.schedule(task, new Date());
 		assertThatExceptionOfType(ExecutionException.class).isThrownBy(() -> future.get(1000, TimeUnit.MILLISECONDS));
@@ -149,7 +149,7 @@ public class ThreadPoolTaskSchedulerTests extends AbstractSchedulingTaskExecutor
 		catch (InterruptedException ex) {
 			throw new IllegalStateException(ex);
 		}
-		assertThat(latch.getCount()).as("latch did not count down,").isEqualTo(0);
+		assertThat(latch.getCount()).as("latch did not count down").isEqualTo(0);
 	}