diff --git a/hudi-client/hudi-flink-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java b/hudi-client/hudi-flink-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
index 5d37a0a25..758d5ec5c 100644
--- a/hudi-client/hudi-flink-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
+++ b/hudi-client/hudi-flink-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
@@ -181,7 +181,11 @@ public class UpsertPartitioner<T extends HoodieRecordPayload<T>> implements Part
               + ", totalInsertBuckets => " + insertBuckets + ", recordsPerBucket => " + insertRecordsPerBucket);
           for (int b = 0; b < insertBuckets; b++) {
             bucketNumbers.add(totalBuckets);
-            recordsPerBucket.add(totalUnassignedInserts / insertBuckets);
+            if (b < insertBuckets - 1) {
+              recordsPerBucket.add(insertRecordsPerBucket);
+            } else {
+              recordsPerBucket.add(totalUnassignedInserts - (insertBuckets - 1) * insertRecordsPerBucket);
+            }
             BucketInfo bucketInfo = new BucketInfo();
             bucketInfo.bucketType = BucketType.INSERT;
             bucketInfo.partitionPath = partitionPath;
diff --git a/hudi-client/hudi-java-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java b/hudi-client/hudi-java-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
index 4b0fcdf95..2e1c33847 100644
--- a/hudi-client/hudi-java-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
+++ b/hudi-client/hudi-java-client/src/main/java/org/apache/hudi/table/action/commit/UpsertPartitioner.java
@@ -179,7 +179,11 @@ public class UpsertPartitioner<T extends HoodieRecordPayload<T>> implements Part
               + ", totalInsertBuckets => " + insertBuckets + ", recordsPerBucket => " + insertRecordsPerBucket);
           for (int b = 0; b < insertBuckets; b++) {
             bucketNumbers.add(totalBuckets);
-            recordsPerBucket.add(totalUnassignedInserts / insertBuckets);
+            if (b < insertBuckets - 1) {
+              recordsPerBucket.add(insertRecordsPerBucket);
+            } else {
+              recordsPerBucket.add(totalUnassignedInserts - (insertBuckets - 1) * insertRecordsPerBucket);
+            }
             BucketInfo bucketInfo = new BucketInfo();
             bucketInfo.bucketType = BucketType.INSERT;
             bucketInfo.partitionPath = partitionPath;