diff --git a/modules/grouping/src/java/org/apache/lucene/search/grouping/FirstPassGroupingCollector.java b/modules/grouping/src/java/org/apache/lucene/search/grouping/FirstPassGroupingCollector.java
index 1b2718980aa..a1cf29410f2 100644
--- a/modules/grouping/src/java/org/apache/lucene/search/grouping/FirstPassGroupingCollector.java
+++ b/modules/grouping/src/java/org/apache/lucene/search/grouping/FirstPassGroupingCollector.java
@@ -229,7 +229,9 @@ public class FirstPassGroupingCollector extends Collector {
       // We already tested that the document is competitive, so replace
       // the bottom group with this new group.
 
-      final CollectedSearchGroup bottomGroup = orderedGroups.pollLast();
+      // java 6-only: final CollectedSearchGroup bottomGroup = orderedGroups.pollLast();
+      final CollectedSearchGroup bottomGroup = orderedGroups.last();
+      orderedGroups.remove(bottomGroup);
       assert orderedGroups.size() == topNGroups -1;
 
       groupMap.remove(bottomGroup.groupValue);