diff --git a/core/trino-main/src/main/java/io/trino/execution/executor/TaskExecutor.java b/core/trino-main/src/main/java/io/trino/execution/executor/TaskExecutor.java
index 900a2331bd84..3bf50f16a3ef 100644
--- a/core/trino-main/src/main/java/io/trino/execution/executor/TaskExecutor.java
+++ b/core/trino-main/src/main/java/io/trino/execution/executor/TaskExecutor.java
@@ -287,8 +287,10 @@ public void removeTask(TaskHandle taskHandle)
         }
 
         // replace blocked splits that were terminated
-        addNewEntrants();
-        recordLeafSplitsSize();
+        synchronized (this) {
+            addNewEntrants();
+            recordLeafSplitsSize();
+        }
     }
 
     private void doRemoveTask(TaskHandle taskHandle)
@@ -480,8 +482,10 @@ private synchronized void recordLeafSplitsSize()
         if (timeDifference > 0) {
             this.leafSplitsSize.add(lastLeafSplitsSize, timeDifference);
             this.lastLeafSplitsSizeRecordTime = now;
-            this.lastLeafSplitsSize = allSplits.size() - intermediateSplits.size();
         }
+        // always record new lastLeafSplitsSize as it might have changed
+        // even if timeDifference is 0
+        this.lastLeafSplitsSize = allSplits.size() - intermediateSplits.size();
     }
 
     private class TaskRunner
diff --git a/core/trino-main/src/test/java/io/trino/execution/executor/TestTaskExecutor.java b/core/trino-main/src/test/java/io/trino/execution/executor/TestTaskExecutor.java
index c5ff6fe528eb..93fefba26d33 100644
--- a/core/trino-main/src/test/java/io/trino/execution/executor/TestTaskExecutor.java
+++ b/core/trino-main/src/test/java/io/trino/execution/executor/TestTaskExecutor.java
@@ -40,6 +40,7 @@
 import static io.airlift.testing.Assertions.assertLessThan;
 import static io.trino.execution.executor.MultilevelSplitQueue.LEVEL_CONTRIBUTION_CAP;
 import static io.trino.execution.executor.MultilevelSplitQueue.LEVEL_THRESHOLD_SECONDS;
+import static java.lang.Double.isNaN;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
@@ -510,9 +511,9 @@ public void testLeafSplitsSize()
         TestingJob driver1 = new TestingJob(ticker, new Phaser(), new Phaser(), new Phaser(), 1, 500);
         TestingJob driver2 = new TestingJob(ticker, new Phaser(), new Phaser(), new Phaser(), 1, 1000 / 500);
 
-        ticker.increment(1, TimeUnit.SECONDS);
+        ticker.increment(0, TimeUnit.SECONDS);
         taskExecutor.enqueueSplits(testTaskHandle, false, ImmutableList.of(driver1, driver2));
-        assertEquals(taskExecutor.getLeafSplitsSize().getAllTime().getMax(), 0.0);
+        assertTrue(isNaN(taskExecutor.getLeafSplitsSize().getAllTime().getMax()));
 
         ticker.increment(1, TimeUnit.SECONDS);
         taskExecutor.enqueueSplits(testTaskHandle, false, ImmutableList.of(driver1));