diff --git a/lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxBulkScorer.java b/lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxBulkScorer.java
index e6dc70502709..1040712cad8c 100644
--- a/lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxBulkScorer.java
+++ b/lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxBulkScorer.java
@@ -54,7 +54,7 @@ private static class BulkScorerAndNext {
     this.scorers =
         PriorityQueue.usingComparator(scorers.size(), Comparator.comparingInt(b -> b.next));
     for (BulkScorer scorer : scorers) {
-      this.scorers.add(new BulkScorerAndNext(scorer));
+      this.scorers.addNoShift(new BulkScorerAndNext(scorer));
     }
   }
 
@@ -85,7 +85,7 @@ public void setScorer(Scorable scorer) throws IOException {
                   @Override
                   public void collect(int doc) throws IOException {
                     final int delta = doc - windowMin;
-                    windowMatches.set(doc - windowMin);
+                    windowMatches.set(delta);
                     windowScores[delta] = Math.max(windowScores[delta], scorer.score());
                   }
                 },
diff --git a/lucene/core/src/java/org/apache/lucene/util/PriorityQueue.java b/lucene/core/src/java/org/apache/lucene/util/PriorityQueue.java
index ec89bb1b2696..43e91457bd96 100644
--- a/lucene/core/src/java/org/apache/lucene/util/PriorityQueue.java
+++ b/lucene/core/src/java/org/apache/lucene/util/PriorityQueue.java
@@ -189,6 +189,18 @@ public final T add(T element) {
     return heap[1];
   }
 
+  /**
+   * Adds an Object to a PriorityQueue without upHeap. Note: only use it when all elements have a
+   * same value.
+   */
+  public final void addNoShift(T element) {
+    // TODO: Check element equalsTo lastElement, if we can get the comparator.
+
+    int index = size + 1;
+    heap[index] = element;
+    size = index;
+  }
+
   /**
    * Adds an Object to a PriorityQueue in log(size) time. It returns the object (if any) that was
    * dropped off the heap because it was full. This can be the given parameter (in case it is