diff --git a/solr/contrib/ltr/src/test/org/apache/solr/ltr/TestLTRReRankingPipeline.java b/solr/contrib/ltr/src/test/org/apache/solr/ltr/TestLTRReRankingPipeline.java
index e8a69422ae0..5f34fe84e2b 100644
--- a/solr/contrib/ltr/src/test/org/apache/solr/ltr/TestLTRReRankingPipeline.java
+++ b/solr/contrib/ltr/src/test/org/apache/solr/ltr/TestLTRReRankingPipeline.java
@@ -192,14 +192,16 @@ public void testDifferentTopN() throws IOException {
 
       // test rerank with different topN cuts
 
+      // cap firstPassTopDocs length at topN
       for (int topN = 1; topN <= 5; topN++) {
-        log.info("rerank {} documents ", topN);
+        log.info("rerank {} documents, return {} documents", topN, topN);
         hits = searcher.search(bqBuilder.build(), 10);
 
         final ScoreDoc[] slice = new ScoreDoc[topN];
         System.arraycopy(hits.scoreDocs, 0, slice, 0, topN);
         hits = new TopDocs(hits.totalHits, slice);
         hits = rescorer.rescore(searcher, hits, topN);
+        assertEquals(topN, hits.scoreDocs.length);
         for (int i = topN - 1, j = 0; i >= 0; i--, j++) {
           if (log.isInfoEnabled()) {
             log.info("doc {} in pos {}", searcher.doc(hits.scoreDocs[j].doc)
@@ -211,6 +213,25 @@ public void testDifferentTopN() throws IOException {
 
         }
       }
+
+      // use full firstPassTopDocs (possibly higher than topN)
+      for (int topN = 1; topN <= 5; topN++) {
+        final TopDocs allHits = searcher.search(bqBuilder.build(), 10);
+        log.info("rerank {} documents, return {} documents", allHits.scoreDocs.length, topN);
+
+        TopDocs rescoredHits = rescorer.rescore(searcher, allHits, topN);
+        assertEquals(topN, rescoredHits.scoreDocs.length);
+        for (int i = allHits.scoreDocs.length-1, j = 0; i >= 0 && j < topN; i--, j++) {
+          if (log.isInfoEnabled()) {
+            log.info("doc {} in pos {}", searcher.doc(rescoredHits.scoreDocs[j].doc)
+                .get("id"), j);
+          }
+          assertEquals(i,
+                  Integer.parseInt(searcher.doc(rescoredHits.scoreDocs[j].doc).get("id")));
+          assertEquals((i + 1) * features.size()*featureWeight, rescoredHits.scoreDocs[j].score, 0.00001);
+
+        }
+      }
     }
   }