diff --git a/flink/v1.15/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java b/flink/v1.15/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
index 58828799255d..220353d75ac4 100644
--- a/flink/v1.15/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
+++ b/flink/v1.15/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
@@ -525,13 +525,7 @@ private DataStream<RowData> distributeDataStream(
                       + "and table is unpartitioned");
               return input;
             } else {
-              if (BucketPartitionerUtil.hasOneBucketField(partitionSpec)) {
-                return input.partitionCustom(
-                    new BucketPartitioner(partitionSpec),
-                    new BucketPartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              } else {
-                return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              }
+              return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
             }
           } else {
             if (partitionSpec.isUnpartitioned()) {
diff --git a/flink/v1.15/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java b/flink/v1.15/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
index 29a0898a1b76..9dae43ce5e58 100644
--- a/flink/v1.15/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
+++ b/flink/v1.15/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
@@ -114,13 +114,19 @@ private void appendRowsToTable(List<RowData> allRows) throws Exception {
                 new BoundedTestSource<>(
                     allRows.stream().map(converter::toExternal).toArray(Row[]::new)),
                 ROW_TYPE_INFO)
-            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE));
+            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE))
+            .partitionCustom(
+                new BucketPartitioner(table.spec()),
+                new BucketPartitionKeySelector(
+                    table.spec(),
+                    table.schema(),
+                    FlinkSink.toFlinkRowType(table.schema(), SimpleDataUtil.FLINK_SCHEMA)));
 
     FlinkSink.forRowData(dataStream)
         .table(table)
         .tableLoader(tableLoader)
         .writeParallelism(parallelism)
-        .distributionMode(DistributionMode.HASH)
+        .distributionMode(DistributionMode.NONE)
         .append();
 
     env.execute("Test Iceberg DataStream");
@@ -157,26 +163,6 @@ public void testSendRecordsToAllBucketsEvenly(TableSchemaType tableSchemaType) t
     }
   }
 
-  /**
-   * Verifies the BucketPartitioner is not used when the PartitionSpec has more than 1 bucket, and
-   * that it should fallback to input.keyBy
-   */
-  @ParameterizedTest
-  @EnumSource(value = TableSchemaType.class, names = "TWO_BUCKETS")
-  public void testMultipleBucketsFallback(TableSchemaType tableSchemaType) throws Exception {
-    setupEnvironment(tableSchemaType);
-    List<RowData> rows = generateTestDataRows();
-
-    appendRowsToTable(rows);
-    TableTestStats stats = extractPartitionResults(tableSchemaType);
-
-    Assertions.assertThat(stats.totalRowCount).isEqualTo(rows.size());
-    for (int i = 0, j = numBuckets; i < numBuckets; i++, j++) {
-      // Only 1 file per bucket will be created when falling back to input.keyBy(...)
-      Assertions.assertThat((int) stats.numFilesPerBucket.get(i)).isEqualTo(1);
-    }
-  }
-
   /**
    * Generating 16 rows to be sent uniformly to all writers (round-robin across 8 writers -> 4
    * buckets)
diff --git a/flink/v1.16/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java b/flink/v1.16/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
index 58828799255d..220353d75ac4 100644
--- a/flink/v1.16/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
+++ b/flink/v1.16/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
@@ -525,13 +525,7 @@ private DataStream<RowData> distributeDataStream(
                       + "and table is unpartitioned");
               return input;
             } else {
-              if (BucketPartitionerUtil.hasOneBucketField(partitionSpec)) {
-                return input.partitionCustom(
-                    new BucketPartitioner(partitionSpec),
-                    new BucketPartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              } else {
-                return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              }
+              return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
             }
           } else {
             if (partitionSpec.isUnpartitioned()) {
diff --git a/flink/v1.16/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java b/flink/v1.16/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
index 29a0898a1b76..9dae43ce5e58 100644
--- a/flink/v1.16/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
+++ b/flink/v1.16/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
@@ -114,13 +114,19 @@ private void appendRowsToTable(List<RowData> allRows) throws Exception {
                 new BoundedTestSource<>(
                     allRows.stream().map(converter::toExternal).toArray(Row[]::new)),
                 ROW_TYPE_INFO)
-            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE));
+            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE))
+            .partitionCustom(
+                new BucketPartitioner(table.spec()),
+                new BucketPartitionKeySelector(
+                    table.spec(),
+                    table.schema(),
+                    FlinkSink.toFlinkRowType(table.schema(), SimpleDataUtil.FLINK_SCHEMA)));
 
     FlinkSink.forRowData(dataStream)
         .table(table)
         .tableLoader(tableLoader)
         .writeParallelism(parallelism)
-        .distributionMode(DistributionMode.HASH)
+        .distributionMode(DistributionMode.NONE)
         .append();
 
     env.execute("Test Iceberg DataStream");
@@ -157,26 +163,6 @@ public void testSendRecordsToAllBucketsEvenly(TableSchemaType tableSchemaType) t
     }
   }
 
-  /**
-   * Verifies the BucketPartitioner is not used when the PartitionSpec has more than 1 bucket, and
-   * that it should fallback to input.keyBy
-   */
-  @ParameterizedTest
-  @EnumSource(value = TableSchemaType.class, names = "TWO_BUCKETS")
-  public void testMultipleBucketsFallback(TableSchemaType tableSchemaType) throws Exception {
-    setupEnvironment(tableSchemaType);
-    List<RowData> rows = generateTestDataRows();
-
-    appendRowsToTable(rows);
-    TableTestStats stats = extractPartitionResults(tableSchemaType);
-
-    Assertions.assertThat(stats.totalRowCount).isEqualTo(rows.size());
-    for (int i = 0, j = numBuckets; i < numBuckets; i++, j++) {
-      // Only 1 file per bucket will be created when falling back to input.keyBy(...)
-      Assertions.assertThat((int) stats.numFilesPerBucket.get(i)).isEqualTo(1);
-    }
-  }
-
   /**
    * Generating 16 rows to be sent uniformly to all writers (round-robin across 8 writers -> 4
    * buckets)
diff --git a/flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java b/flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
index 58828799255d..220353d75ac4 100644
--- a/flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
+++ b/flink/v1.17/flink/src/main/java/org/apache/iceberg/flink/sink/FlinkSink.java
@@ -525,13 +525,7 @@ private DataStream<RowData> distributeDataStream(
                       + "and table is unpartitioned");
               return input;
             } else {
-              if (BucketPartitionerUtil.hasOneBucketField(partitionSpec)) {
-                return input.partitionCustom(
-                    new BucketPartitioner(partitionSpec),
-                    new BucketPartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              } else {
-                return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
-              }
+              return input.keyBy(new PartitionKeySelector(partitionSpec, iSchema, flinkRowType));
             }
           } else {
             if (partitionSpec.isUnpartitioned()) {
diff --git a/flink/v1.17/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java b/flink/v1.17/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
index 29a0898a1b76..9dae43ce5e58 100644
--- a/flink/v1.17/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
+++ b/flink/v1.17/flink/src/test/java/org/apache/iceberg/flink/sink/TestBucketPartitionerFlinkIcebergSink.java
@@ -114,13 +114,19 @@ private void appendRowsToTable(List<RowData> allRows) throws Exception {
                 new BoundedTestSource<>(
                     allRows.stream().map(converter::toExternal).toArray(Row[]::new)),
                 ROW_TYPE_INFO)
-            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE));
+            .map(converter::toInternal, FlinkCompatibilityUtil.toTypeInfo(SimpleDataUtil.ROW_TYPE))
+            .partitionCustom(
+                new BucketPartitioner(table.spec()),
+                new BucketPartitionKeySelector(
+                    table.spec(),
+                    table.schema(),
+                    FlinkSink.toFlinkRowType(table.schema(), SimpleDataUtil.FLINK_SCHEMA)));
 
     FlinkSink.forRowData(dataStream)
         .table(table)
         .tableLoader(tableLoader)
         .writeParallelism(parallelism)
-        .distributionMode(DistributionMode.HASH)
+        .distributionMode(DistributionMode.NONE)
         .append();
 
     env.execute("Test Iceberg DataStream");
@@ -157,26 +163,6 @@ public void testSendRecordsToAllBucketsEvenly(TableSchemaType tableSchemaType) t
     }
   }
 
-  /**
-   * Verifies the BucketPartitioner is not used when the PartitionSpec has more than 1 bucket, and
-   * that it should fallback to input.keyBy
-   */
-  @ParameterizedTest
-  @EnumSource(value = TableSchemaType.class, names = "TWO_BUCKETS")
-  public void testMultipleBucketsFallback(TableSchemaType tableSchemaType) throws Exception {
-    setupEnvironment(tableSchemaType);
-    List<RowData> rows = generateTestDataRows();
-
-    appendRowsToTable(rows);
-    TableTestStats stats = extractPartitionResults(tableSchemaType);
-
-    Assertions.assertThat(stats.totalRowCount).isEqualTo(rows.size());
-    for (int i = 0, j = numBuckets; i < numBuckets; i++, j++) {
-      // Only 1 file per bucket will be created when falling back to input.keyBy(...)
-      Assertions.assertThat((int) stats.numFilesPerBucket.get(i)).isEqualTo(1);
-    }
-  }
-
   /**
    * Generating 16 rows to be sent uniformly to all writers (round-robin across 8 writers -> 4
    * buckets)