diff --git a/lucene/core/src/java/org/apache/lucene/search/AbstractVectorSimilarityQuery.java b/lucene/core/src/java/org/apache/lucene/search/AbstractVectorSimilarityQuery.java
index 393d4b5731f..03dea82578c 100644
--- a/lucene/core/src/java/org/apache/lucene/search/AbstractVectorSimilarityQuery.java
+++ b/lucene/core/src/java/org/apache/lucene/search/AbstractVectorSimilarityQuery.java
@@ -255,6 +255,11 @@ abstract class AbstractVectorSimilarityQuery extends Query {
           new FilteredDocIdSetIterator(acceptDocs) {
             @Override
             protected boolean match(int doc) throws IOException {
+              // Advance the scorer
+              if (!scorer.advanceExact(doc)) {
+                return false;
+              }
+
               // Compute the dot product
               float score = scorer.score();
               cachedScore[0] = score * boost;
diff --git a/lucene/core/src/java/org/apache/lucene/search/VectorScorer.java b/lucene/core/src/java/org/apache/lucene/search/VectorScorer.java
index 4c61ad17af9..29b76e53af2 100644
--- a/lucene/core/src/java/org/apache/lucene/search/VectorScorer.java
+++ b/lucene/core/src/java/org/apache/lucene/search/VectorScorer.java
@@ -87,6 +87,7 @@ abstract class VectorScorer {
 
     @Override
     public float score() throws IOException {
+      assert values.docID() != -1 : getClass().getSimpleName() + " is not positioned";
       return similarity.compare(query, values.vectorValue());
     }
   }
@@ -117,6 +118,7 @@ abstract class VectorScorer {
 
     @Override
     public float score() throws IOException {
+      assert values.docID() != -1 : getClass().getSimpleName() + " is not positioned";
       return similarity.compare(query, values.vectorValue());
     }
   }
diff --git a/lucene/core/src/test/org/apache/lucene/search/BaseVectorSimilarityQueryTestCase.java b/lucene/core/src/test/org/apache/lucene/search/BaseVectorSimilarityQueryTestCase.java
index 98a1e177948..c4f624bae74 100644
--- a/lucene/core/src/test/org/apache/lucene/search/BaseVectorSimilarityQueryTestCase.java
+++ b/lucene/core/src/test/org/apache/lucene/search/BaseVectorSimilarityQueryTestCase.java
@@ -433,8 +433,8 @@ abstract class BaseVectorSimilarityQueryTestCase<
 
   public void testApproximate() throws IOException {
     // Non-restrictive filter, along with similarity to visit a small number of nodes
-    int numFiltered = random().nextInt((numDocs * 4) / 5, numDocs);
-    int targetVisited = random().nextInt(numFiltered / 10, numFiltered / 8);
+    int numFiltered = numDocs - 1;
+    int targetVisited = random().nextInt(1, numFiltered / 10);
 
     V[] vectors = getRandomVectors(numDocs, dim);
     V queryVector = getRandomVector(dim);