diff --git a/lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java b/lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java
index 0566061f357..e91858800a2 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java
@@ -72,9 +72,6 @@ public class TestTopDocsCollector extends LuceneTestCase {
   }
 
   private static final class MyTopDocsCollector extends TopDocsCollector<ScoreDoc> {
-
-    private int idx = 0;
-
     public MyTopDocsCollector(int size) {
       super(new HitQueue(size, false));
     }
@@ -92,11 +89,12 @@ public class TestTopDocsCollector extends LuceneTestCase {
     public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
       final int base = context.docBase;
       return new LeafCollector() {
+        private int idx = 0;
 
         @Override
         public void collect(int doc) {
           ++totalHits;
-          pq.insertWithOverflow(new ScoreDoc(doc + base, scores[idx++]));
+          pq.insertWithOverflow(new ScoreDoc(doc + base, scores[context.docBase + idx++]));
         }
 
         @Override