diff --git a/core/src/main/java/org/elasticsearch/action/percolate/PercolateRequestBuilder.java b/core/src/main/java/org/elasticsearch/action/percolate/PercolateRequestBuilder.java
index 83757dab089..9286601da69 100644
--- a/core/src/main/java/org/elasticsearch/action/percolate/PercolateRequestBuilder.java
+++ b/core/src/main/java/org/elasticsearch/action/percolate/PercolateRequestBuilder.java
@@ -21,7 +21,6 @@ package org.elasticsearch.action.percolate;
 import org.elasticsearch.action.ActionRequestBuilder;
 import org.elasticsearch.action.get.GetRequest;
 import org.elasticsearch.action.support.IndicesOptions;
-import org.elasticsearch.action.support.broadcast.BroadcastOperationRequestBuilder;
 import org.elasticsearch.client.ElasticsearchClient;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
@@ -127,7 +126,7 @@ public class PercolateRequestBuilder extends ActionRequestBuilder<PercolateReque
     /**
      * Delegates to {@link PercolateSourceBuilder#addSort(SortBuilder)}
      */
-    public PercolateRequestBuilder addSort(SortBuilder sort) {
+    public PercolateRequestBuilder addSort(SortBuilder<?> sort) {
         sourceBuilder().addSort(sort);
         return this;
     }
diff --git a/core/src/main/java/org/elasticsearch/action/percolate/PercolateSourceBuilder.java b/core/src/main/java/org/elasticsearch/action/percolate/PercolateSourceBuilder.java
index d687d48fb0c..5a5924f7883 100644
--- a/core/src/main/java/org/elasticsearch/action/percolate/PercolateSourceBuilder.java
+++ b/core/src/main/java/org/elasticsearch/action/percolate/PercolateSourceBuilder.java
@@ -48,13 +48,13 @@ import java.util.Map;
 public class PercolateSourceBuilder extends ToXContentToBytes {
 
     private DocBuilder docBuilder;
-    private QueryBuilder queryBuilder;
+    private QueryBuilder<?> queryBuilder;
     private Integer size;
-    private List<SortBuilder> sorts;
+    private List<SortBuilder<?>> sorts;
     private Boolean trackScores;
     private HighlightBuilder highlightBuilder;
     private List<AggregatorBuilder<?>> aggregationBuilders;
-    private List<PipelineAggregatorBuilder> pipelineAggregationBuilders;
+    private List<PipelineAggregatorBuilder<?>> pipelineAggregationBuilders;
 
     /**
      * Sets the document to run the percolate queries against.
@@ -68,7 +68,7 @@ public class PercolateSourceBuilder extends ToXContentToBytes {
      * Sets a query to reduce the number of percolate queries to be evaluated and score the queries that match based
      * on this query.
      */
-    public PercolateSourceBuilder setQueryBuilder(QueryBuilder queryBuilder) {
+    public PercolateSourceBuilder setQueryBuilder(QueryBuilder<?> queryBuilder) {
         this.queryBuilder = queryBuilder;
         return this;
     }
@@ -98,7 +98,7 @@ public class PercolateSourceBuilder extends ToXContentToBytes {
      *
      * By default the matching percolator queries are returned in an undefined order.
      */
-    public PercolateSourceBuilder addSort(SortBuilder sort) {
+    public PercolateSourceBuilder addSort(SortBuilder<?> sort) {
         if (sorts == null) {
             sorts = new ArrayList<>();
         }
@@ -137,7 +137,7 @@ public class PercolateSourceBuilder extends ToXContentToBytes {
     /**
      * Add an aggregation definition.
      */
-    public PercolateSourceBuilder addAggregation(PipelineAggregatorBuilder aggregationBuilder) {
+    public PercolateSourceBuilder addAggregation(PipelineAggregatorBuilder<?> aggregationBuilder) {
         if (pipelineAggregationBuilders == null) {
             pipelineAggregationBuilders = new ArrayList<>();
         }
@@ -160,10 +160,8 @@ public class PercolateSourceBuilder extends ToXContentToBytes {
         }
         if (sorts != null) {
             builder.startArray("sort");
-            for (SortBuilder sort : sorts) {
-                builder.startObject();
+            for (SortBuilder<?> sort : sorts) {
                 sort.toXContent(builder, params);
-                builder.endObject();
             }
             builder.endArray();
         }
@@ -182,7 +180,7 @@ public class PercolateSourceBuilder extends ToXContentToBytes {
                 }
             }
             if (pipelineAggregationBuilders != null) {
-                for (PipelineAggregatorBuilder aggregation : pipelineAggregationBuilders) {
+                for (PipelineAggregatorBuilder<?> aggregation : pipelineAggregationBuilders) {
                     aggregation.toXContent(builder, params);
                 }
             }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregatorBuilder.java b/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregatorBuilder.java
index 279de65fcae..fd60fa93857 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregatorBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregatorBuilder.java
@@ -502,9 +502,7 @@ public class TopHitsAggregatorBuilder extends AggregatorBuilder<TopHitsAggregato
         if (sorts != null) {
             builder.startArray(SearchSourceBuilder.SORT_FIELD.getPreferredName());
             for (SortBuilder<?> sort : sorts) {
-                    builder.startObject();
                     sort.toXContent(builder, params);
-                    builder.endObject();
             }
             builder.endArray();
         }
diff --git a/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java b/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
index 67d25958310..eae12def5e4 100644
--- a/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
@@ -1051,9 +1051,7 @@ public final class SearchSourceBuilder extends ToXContentToBytes implements Writ
         if (sorts != null) {
             builder.startArray(SORT_FIELD.getPreferredName());
             for (SortBuilder<?> sort : sorts) {
-                builder.startObject();
                 sort.toXContent(builder, params);
-                builder.endObject();
             }
             builder.endArray();
         }
diff --git a/core/src/main/java/org/elasticsearch/search/sort/FieldSortBuilder.java b/core/src/main/java/org/elasticsearch/search/sort/FieldSortBuilder.java
index f6c191cb74a..59d9287d71d 100644
--- a/core/src/main/java/org/elasticsearch/search/sort/FieldSortBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/sort/FieldSortBuilder.java
@@ -42,7 +42,7 @@ import java.util.Objects;
  * A sort builder to sort based on a document field.
  */
 public class FieldSortBuilder extends SortBuilder<FieldSortBuilder> {
-    public static final FieldSortBuilder PROTOTYPE = new FieldSortBuilder("");
+    public static final FieldSortBuilder PROTOTYPE = new FieldSortBuilder("_na_");
     public static final String NAME = "field_sort";
     public static final ParseField NESTED_PATH = new ParseField("nested_path");
     public static final ParseField NESTED_FILTER = new ParseField("nested_filter");
@@ -199,6 +199,7 @@ public class FieldSortBuilder extends SortBuilder<FieldSortBuilder> {
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
         builder.startObject(fieldName);
         builder.field(ORDER_FIELD.getPreferredName(), order);
         if (missing != null) {
@@ -217,6 +218,7 @@ public class FieldSortBuilder extends SortBuilder<FieldSortBuilder> {
             builder.field(NESTED_PATH.getPreferredName(), nestedPath);
         }
         builder.endObject();
+        builder.endObject();
         return builder;
     }
 
diff --git a/core/src/main/java/org/elasticsearch/search/sort/GeoDistanceSortBuilder.java b/core/src/main/java/org/elasticsearch/search/sort/GeoDistanceSortBuilder.java
index 21217129cc4..f3b6a1d49fa 100644
--- a/core/src/main/java/org/elasticsearch/search/sort/GeoDistanceSortBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/sort/GeoDistanceSortBuilder.java
@@ -300,6 +300,7 @@ public class GeoDistanceSortBuilder extends SortBuilder<GeoDistanceSortBuilder>
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
         builder.startObject(NAME);
 
         builder.startArray(fieldName);
@@ -325,6 +326,7 @@ public class GeoDistanceSortBuilder extends SortBuilder<GeoDistanceSortBuilder>
         builder.field(COERCE_FIELD.getPreferredName(), coerce);
         builder.field(IGNORE_MALFORMED_FIELD.getPreferredName(), ignoreMalformed);
 
+        builder.endObject();
         builder.endObject();
         return builder;
     }
diff --git a/core/src/main/java/org/elasticsearch/search/sort/ScoreSortBuilder.java b/core/src/main/java/org/elasticsearch/search/sort/ScoreSortBuilder.java
index c0205935cf8..57371a5cc11 100644
--- a/core/src/main/java/org/elasticsearch/search/sort/ScoreSortBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/sort/ScoreSortBuilder.java
@@ -53,9 +53,11 @@ public class ScoreSortBuilder extends SortBuilder<ScoreSortBuilder> {
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
         builder.startObject(NAME);
         builder.field(ORDER_FIELD.getPreferredName(), order);
         builder.endObject();
+        builder.endObject();
         return builder;
     }
 
diff --git a/core/src/main/java/org/elasticsearch/search/sort/ScriptSortBuilder.java b/core/src/main/java/org/elasticsearch/search/sort/ScriptSortBuilder.java
index 283c3c28390..b79eb6e2147 100644
--- a/core/src/main/java/org/elasticsearch/search/sort/ScriptSortBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/sort/ScriptSortBuilder.java
@@ -179,6 +179,7 @@ public class ScriptSortBuilder extends SortBuilder<ScriptSortBuilder> {
 
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params builderParams) throws IOException {
+        builder.startObject();
         builder.startObject(NAME);
         builder.field(SCRIPT_FIELD.getPreferredName(), script);
         builder.field(TYPE_FIELD.getPreferredName(), type);
@@ -193,6 +194,7 @@ public class ScriptSortBuilder extends SortBuilder<ScriptSortBuilder> {
             builder.field(NESTED_FILTER_FIELD.getPreferredName(), nestedFilter, builderParams);
         }
         builder.endObject();
+        builder.endObject();
         return builder;
     }
 
diff --git a/core/src/test/java/org/elasticsearch/search/sort/AbstractSortTestCase.java b/core/src/test/java/org/elasticsearch/search/sort/AbstractSortTestCase.java
index e6161bc8163..935dfb178b5 100644
--- a/core/src/test/java/org/elasticsearch/search/sort/AbstractSortTestCase.java
+++ b/core/src/test/java/org/elasticsearch/search/sort/AbstractSortTestCase.java
@@ -129,10 +129,7 @@ public abstract class AbstractSortTestCase<T extends SortBuilder<T>> extends EST
             if (randomBoolean()) {
                 builder.prettyPrint();
             }
-            builder.startObject();
             testItem.toXContent(builder, ToXContent.EMPTY_PARAMS);
-            builder.endObject();
-
             XContentParser itemParser = XContentHelper.createParser(builder.bytes());
             itemParser.nextToken();
 
diff --git a/core/src/test/java/org/elasticsearch/search/sort/SortBuilderTests.java b/core/src/test/java/org/elasticsearch/search/sort/SortBuilderTests.java
index 6ddbc678a12..ccb52820e3a 100644
--- a/core/src/test/java/org/elasticsearch/search/sort/SortBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/search/sort/SortBuilderTests.java
@@ -160,15 +160,11 @@ public class SortBuilderTests extends ESTestCase {
                         xContentBuilder.endObject();
                         break;
                     case 2:
-                        xContentBuilder.startObject();
                         builder.toXContent(xContentBuilder, ToXContent.EMPTY_PARAMS);
-                        xContentBuilder.endObject();
                         break;
                     }
                 } else {
-                    xContentBuilder.startObject();
                     builder.toXContent(xContentBuilder, ToXContent.EMPTY_PARAMS);
-                    xContentBuilder.endObject();
                 }
             }
             if (testBuilders.size() > 1) {