diff --git a/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene70/Lucene70Codec.java b/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene70/Lucene70Codec.java
index 6841345dc69..0f397b16f55 100644
--- a/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene70/Lucene70Codec.java
+++ b/lucene/backward-codecs/src/java/org/apache/lucene/codecs/lucene70/Lucene70Codec.java
@@ -55,7 +55,8 @@ public class Lucene70Codec extends Codec {
   private final SegmentInfoFormat segmentInfosFormat = new Lucene70SegmentInfoFormat();
   private final LiveDocsFormat liveDocsFormat = new Lucene50LiveDocsFormat();
   private final CompoundFormat compoundFormat = new Lucene50CompoundFormat();
-  
+  private final DocValuesFormat defaultDVFormat = DocValuesFormat.forName("Lucene70");
+
   private final PostingsFormat postingsFormat = new PerFieldPostingsFormat() {
     @Override
     public PostingsFormat getPostingsFormatForField(String field) {
@@ -66,7 +67,7 @@ public class Lucene70Codec extends Codec {
   private final DocValuesFormat docValuesFormat = new PerFieldDocValuesFormat() {
     @Override
     public DocValuesFormat getDocValuesFormatForField(String field) {
-      throw new IllegalStateException("This codec should only be used for reading, not writing");
+      return defaultDVFormat;
     }
   };
   
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
index bc7b6d8f9e0..6f287978605 100644
--- a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
@@ -1538,7 +1538,7 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
       assertEquals(ndvcf.longValue(), ndvf.longValue()*2);
     }
   }
-  
+
   private void assertBinaryDocValues(LeafReader r, String f, String cf) throws IOException {
     BinaryDocValues bdvf = r.getBinaryDocValues(f);
     BinaryDocValues bdvcf = r.getBinaryDocValues(cf);
@@ -1548,7 +1548,7 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
       assertEquals(getValue(bdvcf), getValue(bdvf)*2);
     }
   }
-  
+
   private void verifyDocValues(Directory dir) throws IOException {
     DirectoryReader reader = DirectoryReader.open(dir);
     for (LeafReaderContext context : reader.leaves()) {
@@ -1576,6 +1576,7 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
     updateNumeric(writer, "1", "ndv2", "ndv2_c", 300L);
     updateBinary(writer, "1", "bdv1", "bdv1_c", 300L);
     updateBinary(writer, "1", "bdv2", "bdv2_c", 300L);
+
     writer.commit();
     verifyDocValues(dir);
     
@@ -1587,6 +1588,77 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
     writer.close();
     dir.close();
   }
+
+  public void testSoftDeletes() throws Exception {
+    Path oldIndexDir = createTempDir("dvupdates");
+    TestUtil.unzip(getDataInputStream(dvUpdatesIndex), oldIndexDir);
+    Directory dir = newFSDirectory(oldIndexDir);
+    verifyUsesDefaultCodec(dir, dvUpdatesIndex);
+    IndexWriterConfig conf = new IndexWriterConfig(new MockAnalyzer(random())).setSoftDeletesField("__soft_delete");
+    IndexWriter writer = new IndexWriter(dir, conf);
+    int maxDoc = writer.maxDoc();
+    writer.updateDocValues(new Term("id", "1"),new NumericDocValuesField("__soft_delete", 1));
+
+    if (random().nextBoolean()) {
+      writer.commit();
+    }
+    writer.forceMerge(1);
+    writer.commit();
+    assertEquals(maxDoc-1, writer.maxDoc());
+    writer.close();
+    dir.close();
+  }
+
+  public void testDocValuesUpdatesWithNewField() throws Exception {
+    Path oldIndexDir = createTempDir("dvupdates");
+    TestUtil.unzip(getDataInputStream(dvUpdatesIndex), oldIndexDir);
+    Directory dir = newFSDirectory(oldIndexDir);
+    verifyUsesDefaultCodec(dir, dvUpdatesIndex);
+
+    // update fields and verify index
+    IndexWriterConfig conf = new IndexWriterConfig(new MockAnalyzer(random()));
+    IndexWriter writer = new IndexWriter(dir, conf);
+    // introduce a new field that we later update
+    writer.addDocument(Arrays.asList(new StringField("id", "" + Integer.MAX_VALUE, Field.Store.NO),
+        new NumericDocValuesField("new_numeric", 1),
+        new BinaryDocValuesField("new_binary", toBytes(1))));
+    writer.updateNumericDocValue(new Term("id", "1"), "new_numeric", 1);
+    writer.updateBinaryDocValue(new Term("id", "1"), "new_binary", toBytes(1));
+
+    writer.commit();
+    Runnable assertDV = () -> {
+      boolean found = false;
+      try (DirectoryReader reader = DirectoryReader.open(dir)) {
+        for (LeafReaderContext ctx : reader.leaves()) {
+          LeafReader leafReader = ctx.reader();
+          TermsEnum id = leafReader.terms("id").iterator();
+          if (id.seekExact(new BytesRef("1"))) {
+            PostingsEnum postings = id.postings(null, PostingsEnum.NONE);
+            NumericDocValues numericDocValues = leafReader.getNumericDocValues("new_numeric");
+            BinaryDocValues binaryDocValues = leafReader.getBinaryDocValues("new_binary");
+            int doc;
+            while ((doc = postings.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) {
+              found = true;
+              assertTrue(binaryDocValues.advanceExact(doc));
+              assertTrue(numericDocValues.advanceExact(doc));
+              assertEquals(1, numericDocValues.longValue());
+              assertEquals(toBytes(1), binaryDocValues.binaryValue());
+            }
+          }
+        }
+      } catch (IOException e) {
+        throw new AssertionError(e);
+      }
+      assertTrue(found);
+    };
+    assertDV.run();
+    // merge all segments
+    writer.forceMerge(1);
+    writer.commit();
+    assertDV.run();
+    writer.close();
+    dir.close();
+  }
   
   // LUCENE-5907
   public void testUpgradeWithNRTReader() throws Exception {