diff --git a/core/trino-main/src/main/java/io/trino/execution/scheduler/ArbitraryDistributionSplitAssigner.java b/core/trino-main/src/main/java/io/trino/execution/scheduler/ArbitraryDistributionSplitAssigner.java
index 6a767e7ff354..b917d2448040 100644
--- a/core/trino-main/src/main/java/io/trino/execution/scheduler/ArbitraryDistributionSplitAssigner.java
+++ b/core/trino-main/src/main/java/io/trino/execution/scheduler/ArbitraryDistributionSplitAssigner.java
@@ -60,6 +60,7 @@ class ArbitraryDistributionSplitAssigner
     private int nextPartitionId;
     private int adaptiveCounter;
     private long targetPartitionSizeInBytes;
+    private long roundedTargetPartitionSizeInBytes;
     private final List<PartitionAssignment> allAssignments = new ArrayList<>();
     private final Map<Optional<HostAddress>, PartitionAssignment> openAssignments = new HashMap<>();
 
@@ -94,6 +95,7 @@ class ArbitraryDistributionSplitAssigner
         this.maxTaskSplitCount = maxTaskSplitCount;
 
         this.targetPartitionSizeInBytes = minTargetPartitionSizeInBytes;
+        this.roundedTargetPartitionSizeInBytes = minTargetPartitionSizeInBytes;
     }
 
     @Override
@@ -200,7 +202,7 @@ private AssignmentResult assignPartitionedSplits(PlanNodeId planNodeId, List<Spl
             Optional<HostAddress> hostRequirement = getHostRequirement(split);
             PartitionAssignment partitionAssignment = openAssignments.get(hostRequirement);
             long splitSizeInBytes = getSplitSizeInBytes(split);
-            if (partitionAssignment != null && ((partitionAssignment.getAssignedDataSizeInBytes() + splitSizeInBytes > targetPartitionSizeInBytes)
+            if (partitionAssignment != null && ((partitionAssignment.getAssignedDataSizeInBytes() + splitSizeInBytes > roundedTargetPartitionSizeInBytes)
                     || (partitionAssignment.getAssignedSplitCount() + 1 > maxTaskSplitCount))) {
                 partitionAssignment.setFull(true);
                 for (PlanNodeId partitionedSourceNodeId : partitionedSources) {
@@ -221,7 +223,8 @@ private AssignmentResult assignPartitionedSplits(PlanNodeId planNodeId, List<Spl
                 if (adaptiveCounter >= adaptiveGrowthPeriod) {
                     targetPartitionSizeInBytes = (long) min(maxTargetPartitionSizeInBytes, ceil(targetPartitionSizeInBytes * adaptiveGrowthFactor));
                     // round to a multiple of minTargetPartitionSizeInBytes so work will be evenly distributed among drivers of a task
-                    targetPartitionSizeInBytes = (targetPartitionSizeInBytes + minTargetPartitionSizeInBytes - 1) / minTargetPartitionSizeInBytes * minTargetPartitionSizeInBytes;
+                    roundedTargetPartitionSizeInBytes = round(targetPartitionSizeInBytes * 1.0 / minTargetPartitionSizeInBytes) * minTargetPartitionSizeInBytes;
+                    verify(roundedTargetPartitionSizeInBytes > 0, "roundedTargetPartitionSizeInBytes %s not positive", roundedTargetPartitionSizeInBytes);
                     adaptiveCounter = 0;
                 }
             }
diff --git a/core/trino-main/src/test/java/io/trino/execution/scheduler/TestArbitraryDistributionSplitAssigner.java b/core/trino-main/src/test/java/io/trino/execution/scheduler/TestArbitraryDistributionSplitAssigner.java
index 2aa6744174b9..cff502fedf13 100644
--- a/core/trino-main/src/test/java/io/trino/execution/scheduler/TestArbitraryDistributionSplitAssigner.java
+++ b/core/trino-main/src/test/java/io/trino/execution/scheduler/TestArbitraryDistributionSplitAssigner.java
@@ -512,6 +512,86 @@ public void testAdaptiveTaskSizing()
                         .build());
     }
 
+    @Test
+    public void testAdaptiveTaskSizingRounding()
+    {
+        Set<PlanNodeId> partitionedSources = ImmutableSet.of(PARTITIONED_1);
+        List<SplitBatch> batches = ImmutableList.of(
+                new SplitBatch(PARTITIONED_1, ImmutableList.of(createSplit(1), createSplit(2), createSplit(3)), false),
+                new SplitBatch(PARTITIONED_1, ImmutableList.of(createSplit(4), createSplit(5), createSplit(6)), false),
+                new SplitBatch(PARTITIONED_1, ImmutableList.of(createSplit(7), createSplit(8), createSplit(9)), true));
+        SplitAssigner splitAssigner = new ArbitraryDistributionSplitAssigner(
+                Optional.of(TEST_CATALOG_HANDLE),
+                partitionedSources,
+                ImmutableSet.of(),
+                1,
+                1.3,
+                100,
+                400,
+                100,
+                5);
+        SplitAssignerTester tester = new SplitAssignerTester();
+        for (SplitBatch batch : batches) {
+            PlanNodeId planNodeId = batch.getPlanNodeId();
+            List<Split> splits = batch.getSplits();
+            boolean noMoreSplits = batch.isNoMoreSplits();
+            tester.update(splitAssigner.assign(planNodeId, createSplitsMultimap(splits), noMoreSplits));
+            tester.checkContainsSplits(planNodeId, splits, false);
+        }
+        tester.update(splitAssigner.finish());
+        List<TaskDescriptor> taskDescriptors = tester.getTaskDescriptors().orElseThrow();
+        assertThat(taskDescriptors).hasSize(5);
+
+        // target size 100, round to 100
+        TaskDescriptor taskDescriptor0 = taskDescriptors.get(0);
+        assertTaskDescriptor(
+                taskDescriptor0,
+                taskDescriptor0.getPartitionId(),
+                ImmutableListMultimap.<PlanNodeId, Split>builder()
+                        .put(PARTITIONED_1, createSplit(1))
+                        .build());
+
+        // target size 130, round to 100
+        TaskDescriptor taskDescriptor1 = taskDescriptors.get(1);
+        assertTaskDescriptor(
+                taskDescriptor1,
+                taskDescriptor1.getPartitionId(),
+                ImmutableListMultimap.<PlanNodeId, Split>builder()
+                        .put(PARTITIONED_1, createSplit(2))
+                        .build());
+
+        // target size 169, round to 200
+        TaskDescriptor taskDescriptor2 = taskDescriptors.get(2);
+        assertTaskDescriptor(
+                taskDescriptor2,
+                taskDescriptor2.getPartitionId(),
+                ImmutableListMultimap.<PlanNodeId, Split>builder()
+                        .put(PARTITIONED_1, createSplit(3))
+                        .put(PARTITIONED_1, createSplit(4))
+                        .build());
+
+        // target size 220, round to 200
+        TaskDescriptor taskDescriptor3 = taskDescriptors.get(3);
+        assertTaskDescriptor(
+                taskDescriptor3,
+                taskDescriptor3.getPartitionId(),
+                ImmutableListMultimap.<PlanNodeId, Split>builder()
+                        .put(PARTITIONED_1, createSplit(5))
+                        .put(PARTITIONED_1, createSplit(6))
+                        .build());
+
+        // target size 286, round to 300
+        TaskDescriptor taskDescriptor4 = taskDescriptors.get(4);
+        assertTaskDescriptor(
+                taskDescriptor4,
+                taskDescriptor4.getPartitionId(),
+                ImmutableListMultimap.<PlanNodeId, Split>builder()
+                        .put(PARTITIONED_1, createSplit(7))
+                        .put(PARTITIONED_1, createSplit(8))
+                        .put(PARTITIONED_1, createSplit(9))
+                        .build());
+    }
+
     private void fuzzTesting(boolean withHostRequirements)
     {
         Set<PlanNodeId> partitionedSources = new HashSet<>();