diff --git a/flink-runtime/src/test/java/org/apache/flink/runtime/scheduler/adaptivebatch/AdaptiveBatchSchedulerTest.java b/flink-runtime/src/test/java/org/apache/flink/runtime/scheduler/adaptivebatch/AdaptiveBatchSchedulerTest.java
index 9b5b1c3d33403..143023d91dc54 100644
--- a/flink-runtime/src/test/java/org/apache/flink/runtime/scheduler/adaptivebatch/AdaptiveBatchSchedulerTest.java
+++ b/flink-runtime/src/test/java/org/apache/flink/runtime/scheduler/adaptivebatch/AdaptiveBatchSchedulerTest.java
@@ -25,7 +25,7 @@
 import org.apache.flink.core.failure.FailureEnricher;
 import org.apache.flink.core.failure.TestingFailureEnricher;
 import org.apache.flink.runtime.concurrent.ComponentMainThreadExecutor;
-import org.apache.flink.runtime.concurrent.ComponentMainThreadExecutorServiceAdapter;
+import org.apache.flink.runtime.concurrent.NoMainThreadCheckComponentMainThreadExecutor;
 import org.apache.flink.runtime.execution.ExecutionState;
 import org.apache.flink.runtime.executiongraph.DefaultExecutionGraph;
 import org.apache.flink.runtime.executiongraph.Execution;
@@ -49,7 +49,6 @@
 import org.apache.flink.runtime.scheduler.exceptionhistory.RootExceptionHistoryEntry;
 import org.apache.flink.runtime.taskmanager.TaskExecutionState;
 import org.apache.flink.runtime.testtasks.NoOpInvokable;
-import org.apache.flink.runtime.testutils.DirectScheduledExecutorService;
 import org.apache.flink.testutils.TestingUtils;
 import org.apache.flink.testutils.executor.TestExecutorExtension;
 import org.apache.flink.util.concurrent.ManuallyTriggeredScheduledExecutor;
@@ -68,12 +67,9 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import java.util.stream.LongStream;
 
@@ -106,55 +102,12 @@ void setUp() {
         // execution semantics without strict thread identity checks. This fixes flaky test
         // failures (FLINK-38970) caused by main thread constraint violations when
         // CompletableFuture callbacks are dispatched from background IO executor threads.
-        // The synchronous execution is preserved while eliminating the race condition.
-        mainThreadExecutor = new SynchronousComponentMainThreadExecutor();
+        // No-op thread check avoids flakiness from FLINK-38970: scheduler callbacks
+        // can complete on background IO threads rather than the main thread.
+        mainThreadExecutor = new NoMainThreadCheckComponentMainThreadExecutor();
         taskRestartExecutor = new ManuallyTriggeredScheduledExecutor();
     }
 
-    /**
-     * A synchronous ComponentMainThreadExecutor that runs tasks immediately on the calling thread.
-     * Unlike {@link ComponentMainThreadExecutorServiceAdapter#forMainThread()}, this executor does
-     * not perform strict thread identity checks, avoiding flaky failures when CompletableFuture
-     * callbacks are dispatched from background threads.
-     */
-    private static class SynchronousComponentMainThreadExecutor
-            implements ComponentMainThreadExecutor {
-        private final DirectScheduledExecutorService executor =
-                new DirectScheduledExecutorService();
-
-        @Override
-        public void assertRunningInMainThread() {
-            // No-op: Skip thread assertion to avoid flaky failures
-        }
-
-        @Override
-        public void execute(Runnable command) {
-            executor.execute(command);
-        }
-
-        @Override
-        public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
-            return executor.schedule(command, delay, unit);
-        }
-
-        @Override
-        public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
-            return executor.schedule(callable, delay, unit);
-        }
-
-        @Override
-        public ScheduledFuture<?> scheduleAtFixedRate(
-                Runnable command, long initialDelay, long period, TimeUnit unit) {
-            return executor.scheduleAtFixedRate(command, initialDelay, period, unit);
-        }
-
-        @Override
-        public ScheduledFuture<?> scheduleWithFixedDelay(
-                Runnable command, long initialDelay, long delay, TimeUnit unit) {
-            return executor.scheduleWithFixedDelay(command, initialDelay, delay, unit);
-        }
-    }
-
     @Test
     void testVertexInitializationFailureIsLabeled() throws Exception {
         final JobGraph jobGraph = createBrokenJobGraph();