diff --git a/lucene/core/src/java/org/apache/lucene/store/IndexInput.java b/lucene/core/src/java/org/apache/lucene/store/IndexInput.java
index 8c9186ceb36..4e36fe4e3b9 100644
--- a/lucene/core/src/java/org/apache/lucene/store/IndexInput.java
+++ b/lucene/core/src/java/org/apache/lucene/store/IndexInput.java
@@ -149,6 +149,11 @@ public abstract class IndexInput extends DataInput implements Cloneable,Closeabl
           slice.seek(pos);
           return slice.readLong();
         }
+
+        @Override
+        public String toString() {
+          return "RandomAccessInput(" + IndexInput.this.toString() + ")";
+        }
       };
     }
   }
diff --git a/lucene/core/src/test/org/apache/lucene/index/TestIndexingSequenceNumbers.java b/lucene/core/src/test/org/apache/lucene/index/TestIndexingSequenceNumbers.java
index f4fc2f0b995..9c7a6f9666f 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestIndexingSequenceNumbers.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestIndexingSequenceNumbers.java
@@ -17,6 +17,14 @@
 
 package org.apache.lucene.index;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.NumericDocValuesField;
@@ -28,17 +36,10 @@ import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.LuceneTestCase.SuppressCodecs;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.TestUtil;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.atomic.AtomicInteger;
-
 public class TestIndexingSequenceNumbers extends LuceneTestCase {
 
   public void testBasic() throws Exception {
@@ -316,6 +317,9 @@ public class TestIndexingSequenceNumbers extends LuceneTestCase {
     final IndexWriter w = new IndexWriter(dir, iwc);
 
     final int numThreads = TestUtil.nextInt(random(), 2, 10);
+    if (VERBOSE) {
+      System.out.println("TEST: numThreads=" + numThreads);
+    }
     Thread[] threads = new Thread[numThreads];
     //System.out.println("TEST: iter=" + iter + " opCount=" + opCount + " idCount=" + idCount + " threadCount=" + threads.length);
     final CountDownLatch startingGun = new CountDownLatch(1);
@@ -383,6 +387,7 @@ public class TestIndexingSequenceNumbers extends LuceneTestCase {
             }
           }
         };
+      threads[i].setName("thread" + i);
       threads[i].start();
     }
     startingGun.countDown();
@@ -416,9 +421,8 @@ public class TestIndexingSequenceNumbers extends LuceneTestCase {
         for(Operation op : threadOps.get(threadID)) {
           if (op.seqNo <= commitSeqNo && op.seqNo > seqNos[op.id]) {
             seqNos[op.id] = op.seqNo;
-            if (op.what == 0) {
-              expectedThreadIDs[op.id] = threadID;
-            }
+            assert op.what == 0;
+            expectedThreadIDs[op.id] = threadID;
           }
 
           assertTrue(op.seqNo > lastSeqNo);
@@ -437,9 +441,9 @@ public class TestIndexingSequenceNumbers extends LuceneTestCase {
         // We pre-add all ids up front:
         assert expectedThreadIDs[id] != -1;
         assertEquals(1, hits.totalHits);
-        int actualThreadID = (int) docValues.get(id);
+        int actualThreadID = (int) docValues.get(hits.scoreDocs[0].doc);
         if (expectedThreadIDs[id] != actualThreadID) {
-          System.out.println("FAIL: commit=" + i + " (of " + commits.size() + ") id=" + id + " expectedThreadID=" + expectedThreadIDs[id] + " vs actualThreadID=" + actualThreadID + " commitSeqNo=" + commitSeqNo + " numThreads=" + numThreads);
+          System.out.println("FAIL: commit=" + i + " (of " + commits.size() + ") id=" + id + " expectedThreadID=" + expectedThreadIDs[id] + " vs actualThreadID=" + actualThreadID + " commitSeqNo=" + commitSeqNo + " numThreads=" + numThreads + " reader=" + r + " commit=" + indexCommits.get(i));
           for(int threadID=0;threadID<threadOps.size();threadID++) {
             for(Operation op : threadOps.get(threadID)) {
               if (id == op.id) {
@@ -447,7 +451,7 @@ public class TestIndexingSequenceNumbers extends LuceneTestCase {
               }
             }
           }
-          assertEquals("id=" + id, expectedThreadIDs[id], actualThreadID);
+          assertEquals("id=" + id + " docID=" + hits.scoreDocs[0].doc, expectedThreadIDs[id], actualThreadID);
         }
       }
       w.close();