diff --git a/server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java b/server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java
index 82baef2780943..86674617272a7 100644
--- a/server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java
+++ b/server/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java
@@ -445,13 +445,7 @@ private static ParseContext nestedContext(ParseContext context, ObjectMapper map
         if (idField != null) {
             // We just need to store the id as indexed field, so that IndexWriter#deleteDocuments(term) can then
             // delete it when the root document is deleted too.
-            if (idField.stringValue() != null) {
-                // backward compat with 5.x
-                // TODO: Remove on 7.0
-                nestedDoc.add(new Field(IdFieldMapper.NAME, idField.stringValue(), IdFieldMapper.Defaults.NESTED_FIELD_TYPE));
-            } else {
-                nestedDoc.add(new Field(IdFieldMapper.NAME, idField.binaryValue(), IdFieldMapper.Defaults.NESTED_FIELD_TYPE));
-            }
+            nestedDoc.add(new Field(IdFieldMapper.NAME, idField.binaryValue(), IdFieldMapper.Defaults.NESTED_FIELD_TYPE));
         } else {
             throw new IllegalStateException("The root document of a nested document should have an _id field");
         }
diff --git a/server/src/main/java/org/elasticsearch/index/mapper/TypeFieldMapper.java b/server/src/main/java/org/elasticsearch/index/mapper/TypeFieldMapper.java
index 537cdbafe9522..03bd9f64ca4a1 100644
--- a/server/src/main/java/org/elasticsearch/index/mapper/TypeFieldMapper.java
+++ b/server/src/main/java/org/elasticsearch/index/mapper/TypeFieldMapper.java
@@ -43,7 +43,6 @@
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.fielddata.IndexFieldData;
 import org.elasticsearch.index.fielddata.plain.ConstantIndexFieldData;
-import org.elasticsearch.index.fielddata.plain.DocValuesIndexFieldData;
 import org.elasticsearch.index.query.QueryShardContext;
 
 import java.io.IOException;
@@ -114,13 +113,8 @@ public String typeName() {
 
         @Override
         public IndexFieldData.Builder fielddataBuilder(String fullyQualifiedIndexName) {
-            if (hasDocValues()) {
-                return new DocValuesIndexFieldData.Builder();
-            } else {
-                // means the index has a single type and the type field is implicit
-                Function<MapperService, String> typeFunction = mapperService -> mapperService.documentMapper().type();
-                return new ConstantIndexFieldData.Builder(typeFunction);
-            }
+            Function<MapperService, String> typeFunction = mapperService -> mapperService.documentMapper().type();
+            return new ConstantIndexFieldData.Builder(typeFunction);
         }
 
         @Override