diff --git a/docs/content/ingestion/tasks.md b/docs/content/ingestion/tasks.md
index 64fa14679fc..507f589f459 100644
--- a/docs/content/ingestion/tasks.md
+++ b/docs/content/ingestion/tasks.md
@@ -162,6 +162,7 @@ Append tasks append a list of segments together into a single segment (one after
     "id": <task_id>,
     "dataSource": <task_datasource>,
     "segments": <JSON list of DataSegment objects to append>,
+    "buildV9Directly": <true or false, default true>,
     "aggregations": <optional list of aggregators>
 }
 ```
@@ -180,6 +181,7 @@ The grammar is:
     "dataSource": <task_datasource>,
     "aggregations": <list of aggregators>,
     "rollup": <whether or not to rollup data during a merge>,
+    "buildV9Directly": <true or false, default true>,
     "segments": <JSON list of DataSegment objects to merge>
 }
 ```
diff --git a/indexing-service/src/main/java/io/druid/indexing/common/task/AppendTask.java b/indexing-service/src/main/java/io/druid/indexing/common/task/AppendTask.java
index 36fd093c160..b53a6cd64a1 100644
--- a/indexing-service/src/main/java/io/druid/indexing/common/task/AppendTask.java
+++ b/indexing-service/src/main/java/io/druid/indexing/common/task/AppendTask.java
@@ -29,6 +29,7 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
 import io.druid.indexing.common.TaskToolbox;
 import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.segment.IndexMerger;
 import io.druid.segment.IndexSpec;
 import io.druid.segment.IndexableAdapter;
 import io.druid.segment.QueryableIndexIndexableAdapter;
@@ -49,9 +50,10 @@ import java.util.Map;
  */
 public class AppendTask extends MergeTaskBase
 {
-
+  private static final Boolean defaultBuildV9Directly = Boolean.TRUE;
   private final IndexSpec indexSpec;
   private final List<AggregatorFactory> aggregators;
+  private final Boolean buildV9Directly;
 
   @JsonCreator
   public AppendTask(
@@ -60,12 +62,14 @@ public class AppendTask extends MergeTaskBase
       @JsonProperty("segments") List<DataSegment> segments,
       @JsonProperty("aggregations") List<AggregatorFactory> aggregators,
       @JsonProperty("indexSpec") IndexSpec indexSpec,
+      @JsonProperty("buildV9Directly") Boolean buildV9Directly,
       @JsonProperty("context") Map<String, Object> context
   )
   {
     super(id, dataSource, segments, context);
     this.indexSpec = indexSpec == null ? new IndexSpec() : indexSpec;
     this.aggregators = aggregators;
+    this.buildV9Directly = buildV9Directly == null ? defaultBuildV9Directly : buildV9Directly;
   }
 
   @Override
@@ -131,7 +135,8 @@ public class AppendTask extends MergeTaskBase
       );
     }
 
-    return toolbox.getIndexMerger().append(
+    IndexMerger indexMerger = buildV9Directly ? toolbox.getIndexMergerV9() : toolbox.getIndexMerger();
+    return indexMerger.append(
         adapters,
         aggregators == null ? null : aggregators.toArray(new AggregatorFactory[aggregators.size()]),
         outDir,
diff --git a/indexing-service/src/main/java/io/druid/indexing/common/task/MergeTask.java b/indexing-service/src/main/java/io/druid/indexing/common/task/MergeTask.java
index 9df49936e09..7cc914f0df5 100644
--- a/indexing-service/src/main/java/io/druid/indexing/common/task/MergeTask.java
+++ b/indexing-service/src/main/java/io/druid/indexing/common/task/MergeTask.java
@@ -29,6 +29,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import io.druid.indexing.common.TaskToolbox;
 import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.segment.IndexMerger;
 import io.druid.segment.IndexSpec;
 import io.druid.segment.QueryableIndex;
 import io.druid.timeline.DataSegment;
@@ -42,10 +43,12 @@ import java.util.Map;
  */
 public class MergeTask extends MergeTaskBase
 {
+  private static final Boolean defaultBuildV9Directly = Boolean.TRUE;
   @JsonIgnore
   private final List<AggregatorFactory> aggregators;
   private final Boolean rollup;
   private final IndexSpec indexSpec;
+  private final Boolean buildV9Directly;
 
   @JsonCreator
   public MergeTask(
@@ -55,6 +58,7 @@ public class MergeTask extends MergeTaskBase
       @JsonProperty("aggregations") List<AggregatorFactory> aggregators,
       @JsonProperty("rollup") Boolean rollup,
       @JsonProperty("indexSpec") IndexSpec indexSpec,
+      @JsonProperty("buildV9Directly") Boolean buildV9Directly,
       @JsonProperty("context") Map<String, Object> context
   )
   {
@@ -62,13 +66,15 @@ public class MergeTask extends MergeTaskBase
     this.aggregators = Preconditions.checkNotNull(aggregators, "null aggregations");
     this.rollup = rollup == null ? Boolean.TRUE : rollup;
     this.indexSpec = indexSpec == null ? new IndexSpec() : indexSpec;
+    this.buildV9Directly = buildV9Directly == null ? defaultBuildV9Directly : buildV9Directly;
   }
 
   @Override
   public File merge(final TaskToolbox toolbox, final Map<DataSegment, File> segments, final File outDir)
       throws Exception
   {
-    return toolbox.getIndexMerger().mergeQueryableIndex(
+    IndexMerger indexMerger = buildV9Directly ? toolbox.getIndexMergerV9() : toolbox.getIndexMerger();
+    return indexMerger.mergeQueryableIndex(
         Lists.transform(
             ImmutableList.copyOf(segments.values()),
             new Function<File, QueryableIndex>()
diff --git a/indexing-service/src/test/java/io/druid/indexing/common/task/TaskSerdeTest.java b/indexing-service/src/test/java/io/druid/indexing/common/task/TaskSerdeTest.java
index 7003e4d816f..f23f4f392ef 100644
--- a/indexing-service/src/test/java/io/druid/indexing/common/task/TaskSerdeTest.java
+++ b/indexing-service/src/test/java/io/druid/indexing/common/task/TaskSerdeTest.java
@@ -298,6 +298,7 @@ public class TaskSerdeTest
         aggregators,
         true,
         indexSpec,
+        true,
         null
     );
 
@@ -529,6 +530,7 @@ public class TaskSerdeTest
             new CountAggregatorFactory("cnt")
         ),
         indexSpec,
+        true,
         null
     );