diff --git a/src/main/java/org/elasticsearch/index/cache/IndexCache.java b/src/main/java/org/elasticsearch/index/cache/IndexCache.java
index beeeed8dc26..589c449b417 100644
--- a/src/main/java/org/elasticsearch/index/cache/IndexCache.java
+++ b/src/main/java/org/elasticsearch/index/cache/IndexCache.java
@@ -65,6 +65,13 @@ public class IndexCache extends AbstractIndexComponent implements CloseableCompo
         return filterCache;
     }
 
+    /**
+     * Return the {@link FixedBitSetFilterCache} for this index.
+     */
+    public FixedBitSetFilterCache fixedBitSetFilterCache() {
+        return fixedBitSetFilterCache;
+    }
+
     public QueryParserCache queryParserCache() {
         return this.queryParserCache;
     }
diff --git a/src/main/java/org/elasticsearch/index/engine/Engine.java b/src/main/java/org/elasticsearch/index/engine/Engine.java
index a41814dd191..dd9c6ab845f 100644
--- a/src/main/java/org/elasticsearch/index/engine/Engine.java
+++ b/src/main/java/org/elasticsearch/index/engine/Engine.java
@@ -34,6 +34,7 @@ import org.elasticsearch.common.lucene.uid.Versions;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.index.VersionType;
+import org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilter;
 import org.elasticsearch.index.deletionpolicy.SnapshotIndexCommit;
 import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.ParseContext.Document;
@@ -650,13 +651,13 @@ public interface Engine extends IndexShardComponent, CloseableComponent {
         private final String[] filteringAliases;
         private final Filter aliasFilter;
         private final String[] types;
-        private final Filter parentFilter;
+        private final FixedBitSetFilter parentFilter;
         private final Operation.Origin origin;
 
         private final long startTime;
         private long endTime;
 
-        public DeleteByQuery(Query query, BytesReference source, @Nullable String[] filteringAliases, @Nullable Filter aliasFilter, Filter parentFilter, Operation.Origin origin, long startTime, String... types) {
+        public DeleteByQuery(Query query, BytesReference source, @Nullable String[] filteringAliases, @Nullable Filter aliasFilter, FixedBitSetFilter parentFilter, Operation.Origin origin, long startTime, String... types) {
             this.query = query;
             this.source = source;
             this.types = types;
@@ -691,7 +692,7 @@ public interface Engine extends IndexShardComponent, CloseableComponent {
             return parentFilter != null;
         }
 
-        public Filter parentFilter() {
+        public FixedBitSetFilter parentFilter() {
             return parentFilter;
         }
 
diff --git a/src/main/java/org/elasticsearch/index/search/nested/IncludeNestedDocsQuery.java b/src/main/java/org/elasticsearch/index/search/nested/IncludeNestedDocsQuery.java
index cf74def8cb7..32d449c3f79 100644
--- a/src/main/java/org/elasticsearch/index/search/nested/IncludeNestedDocsQuery.java
+++ b/src/main/java/org/elasticsearch/index/search/nested/IncludeNestedDocsQuery.java
@@ -25,7 +25,7 @@ import org.apache.lucene.index.Term;
 import org.apache.lucene.search.*;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.FixedBitSet;
-import org.elasticsearch.common.lucene.docset.DocIdSets;
+import org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilter;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -39,7 +39,7 @@ import java.util.Set;
  */
 public class IncludeNestedDocsQuery extends Query {
 
-    private final Filter parentFilter;
+    private final FixedBitSetFilter parentFilter;
     private final Query parentQuery;
 
     // If we are rewritten, this is the original childQuery we
@@ -50,7 +50,7 @@ public class IncludeNestedDocsQuery extends Query {
     private final Query origParentQuery;
 
 
-    public IncludeNestedDocsQuery(Query parentQuery, Filter parentFilter) {
+    public IncludeNestedDocsQuery(Query parentQuery, FixedBitSetFilter parentFilter) {
         this.origParentQuery = parentQuery;
         this.parentQuery = parentQuery;
         this.parentFilter = parentFilter;
@@ -80,9 +80,9 @@ public class IncludeNestedDocsQuery extends Query {
 
         private final Query parentQuery;
         private final Weight parentWeight;
-        private final Filter parentsFilter;
+        private final FixedBitSetFilter parentsFilter;
 
-        IncludeNestedDocsWeight(Query parentQuery, Weight parentWeight, Filter parentsFilter) {
+        IncludeNestedDocsWeight(Query parentQuery, Weight parentWeight, FixedBitSetFilter parentsFilter) {
             this.parentQuery = parentQuery;
             this.parentWeight = parentWeight;
             this.parentsFilter = parentsFilter;
@@ -112,20 +112,11 @@ public class IncludeNestedDocsQuery extends Query {
                 return null;
             }
 
-            DocIdSet parents = parentsFilter.getDocIdSet(context, acceptDocs);
+            FixedBitSet parents = parentsFilter.getDocIdSet(context, acceptDocs);
             if (parents == null) {
                 // No matches
                 return null;
             }
-            if (!(parents instanceof FixedBitSet)) {
-                if (parents.isCacheable()) {
-                    // the filter is cached, yet not with the right type
-                    throw new IllegalStateException("parentFilter must return FixedBitSet; got " + parents);
-                } else {
-                    // may happen if the filter cache type is none
-                    parents = DocIdSets.toFixedBitSet(parents.iterator(), context.reader().maxDoc());
-                }
-            }
 
             int firstParentDoc = parentScorer.nextDoc();
             if (firstParentDoc == DocIdSetIterator.NO_MORE_DOCS) {
diff --git a/src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java b/src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java
index 32660589d77..48f019ee5fb 100644
--- a/src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java
+++ b/src/main/java/org/elasticsearch/index/shard/service/InternalIndexShard.java
@@ -48,6 +48,8 @@ import org.elasticsearch.index.aliases.IndexAliasesService;
 import org.elasticsearch.index.cache.IndexCache;
 import org.elasticsearch.index.cache.filter.FilterCacheStats;
 import org.elasticsearch.index.cache.filter.ShardFilterCache;
+import org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilter;
+import org.elasticsearch.index.cache.fixedbitset.ShardFixedBitSetFilterCache;
 import org.elasticsearch.index.cache.id.IdCacheStats;
 import org.elasticsearch.index.cache.query.ShardQueryCache;
 import org.elasticsearch.index.codec.CodecService;
@@ -68,7 +70,6 @@ import org.elasticsearch.index.merge.scheduler.MergeSchedulerProvider;
 import org.elasticsearch.index.percolator.PercolatorQueriesRegistry;
 import org.elasticsearch.index.percolator.stats.ShardPercolateService;
 import org.elasticsearch.index.query.IndexQueryParserService;
-import org.elasticsearch.index.cache.fixedbitset.ShardFixedBitSetFilterCache;
 import org.elasticsearch.index.refresh.RefreshStats;
 import org.elasticsearch.index.search.nested.NonNestedDocsFilter;
 import org.elasticsearch.index.search.stats.SearchStats;
@@ -465,7 +466,7 @@ public class InternalIndexShard extends AbstractIndexShardComponent implements I
         query = filterQueryIfNeeded(query, types);
 
         Filter aliasFilter = indexAliasesService.aliasFilter(filteringAliases);
-        Filter parentFilter = mapperService.hasNested() ? indexCache.filter().cache(NonNestedDocsFilter.INSTANCE) : null;
+        FixedBitSetFilter parentFilter = mapperService.hasNested() ? indexCache.fixedBitSetFilterCache().getFixedBitSetFilter(NonNestedDocsFilter.INSTANCE) : null;
         return new Engine.DeleteByQuery(query, source, filteringAliases, aliasFilter, parentFilter, origin, startTime, types);
     }