diff --git a/build.xml b/build.xml
index 28152182a84c..5c05202c554e 100644
--- a/build.xml
+++ b/build.xml
@@ -741,7 +741,7 @@
           <dependency groupId="org.apache.lucene" artifactId="lucene-core" version="9.8.0" />
           <dependency groupId="org.apache.lucene" artifactId="lucene-analysis-common" version="9.8.0" />
           <dependency groupId="org.apache.lucene" artifactId="lucene-backward-codecs" version="9.8.0" />
-          <dependency groupId="io.github.jbellis" artifactId="jvector" version="4.0.0-rc.3" />
+          <dependency groupId="io.github.jbellis" artifactId="jvector" version="4.0.0-rc.5" />
           <dependency groupId="com.bpodgursky" artifactId="jbool_expressions" version="1.14" scope="test"/>
 
           <dependency groupId="com.carrotsearch.randomizedtesting" artifactId="randomizedtesting-runner" version="2.1.2" scope="test">
diff --git a/src/java/org/apache/cassandra/index/sai/disk/vector/CassandraDiskAnn.java b/src/java/org/apache/cassandra/index/sai/disk/vector/CassandraDiskAnn.java
index 92544f07e4bc..2e1e058e6c91 100644
--- a/src/java/org/apache/cassandra/index/sai/disk/vector/CassandraDiskAnn.java
+++ b/src/java/org/apache/cassandra/index/sai/disk/vector/CassandraDiskAnn.java
@@ -27,7 +27,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import io.github.jbellis.jvector.graph.GraphIndex;
+import io.github.jbellis.jvector.graph.ImmutableGraphIndex;
 import io.github.jbellis.jvector.graph.GraphSearcher;
 import io.github.jbellis.jvector.graph.disk.feature.FeatureId;
 import io.github.jbellis.jvector.graph.disk.OnDiskGraphIndex;
@@ -72,7 +72,7 @@ public class CassandraDiskAnn
     private final FileHandle graphHandle;
     private final OnDiskOrdinalsMap ordinalsMap;
     private final Set<FeatureId> features;
-    private final GraphIndex graph;
+    private final ImmutableGraphIndex graph;
     private final VectorSimilarityFunction similarityFunction;
     @Nullable
     private final CompressedVectors compressedVectors;
@@ -231,7 +231,7 @@ public CloseableIterator<RowIdWithScore> search(VectorFloat<?> queryVector,
         searcher.usePruning(usePruning);
         try
         {
-            var view = (GraphIndex.ScoringView) searcher.getView();
+            var view = (ImmutableGraphIndex.ScoringView) searcher.getView();
             SearchScoreProvider ssp;
             // FusedADC can no longer be written due to jvector upgrade. However, it's possible these index files
             // still exist, so we have to support them.
@@ -311,9 +311,9 @@ public OrdinalsView getOrdinalsView()
         return ordinalsMap.getOrdinalsView();
     }
 
-    public GraphIndex.ScoringView getView()
+    public ImmutableGraphIndex.ScoringView getView()
     {
-        return (GraphIndex.ScoringView) graph.getView();
+        return (ImmutableGraphIndex.ScoringView) graph.getView();
     }
 
     public boolean containsUnitVectors()
diff --git a/src/java/org/apache/cassandra/index/sai/disk/vector/CloseableReranker.java b/src/java/org/apache/cassandra/index/sai/disk/vector/CloseableReranker.java
index b85b33c81b55..0415b9eb4bcc 100644
--- a/src/java/org/apache/cassandra/index/sai/disk/vector/CloseableReranker.java
+++ b/src/java/org/apache/cassandra/index/sai/disk/vector/CloseableReranker.java
@@ -20,21 +20,21 @@
 
 import java.io.Closeable;
 
-import io.github.jbellis.jvector.graph.GraphIndex;
+import io.github.jbellis.jvector.graph.ImmutableGraphIndex;
 import io.github.jbellis.jvector.graph.similarity.ScoreFunction;
 import io.github.jbellis.jvector.vector.VectorSimilarityFunction;
 import io.github.jbellis.jvector.vector.types.VectorFloat;
 import org.apache.cassandra.io.util.FileUtils;
 
 /**
- * An ExactScoreFunction that closes the underlying {@link GraphIndex.ScoringView} when closed.
+ * An ExactScoreFunction that closes the underlying {@link ImmutableGraphIndex.ScoringView} when closed.
  */
 public class CloseableReranker implements ScoreFunction.ExactScoreFunction, Closeable
 {
-    private final GraphIndex.ScoringView view;
+    private final ImmutableGraphIndex.ScoringView view;
     private final ExactScoreFunction scoreFunction;
 
-    public CloseableReranker(VectorSimilarityFunction similarityFunction, VectorFloat<?> queryVector, GraphIndex.ScoringView view)
+    public CloseableReranker(VectorSimilarityFunction similarityFunction, VectorFloat<?> queryVector, ImmutableGraphIndex.ScoringView view)
     {
         this.view = view;
         this.scoreFunction = view.rerankerFor(queryVector, similarityFunction);
diff --git a/src/java/org/apache/cassandra/index/sai/disk/vector/CompactionGraph.java b/src/java/org/apache/cassandra/index/sai/disk/vector/CompactionGraph.java
index c2339861037f..a9be73b1177b 100644
--- a/src/java/org/apache/cassandra/index/sai/disk/vector/CompactionGraph.java
+++ b/src/java/org/apache/cassandra/index/sai/disk/vector/CompactionGraph.java
@@ -372,7 +372,7 @@ public long addGraphNode(InsertionResult result)
     public SegmentMetadata.ComponentMetadataMap flush() throws IOException
     {
         // header is required to write the postings, but we need to recreate the writer after that with an accurate OrdinalMapper
-        writer.writeHeader();
+        writer.writeHeader(builder.getGraph().getView());
         writer.close();
 
         int nInProgress = builder.insertsInProgress();
diff --git a/test/unit/org/apache/cassandra/index/sai/disk/vector/BruteForceRowIdIteratorTest.java b/test/unit/org/apache/cassandra/index/sai/disk/vector/BruteForceRowIdIteratorTest.java
index 22658da82ac7..bdd3e0fd3958 100644
--- a/test/unit/org/apache/cassandra/index/sai/disk/vector/BruteForceRowIdIteratorTest.java
+++ b/test/unit/org/apache/cassandra/index/sai/disk/vector/BruteForceRowIdIteratorTest.java
@@ -22,7 +22,7 @@
 
 import org.junit.Test;
 
-import io.github.jbellis.jvector.graph.GraphIndex;
+import io.github.jbellis.jvector.graph.ImmutableGraphIndex;
 import io.github.jbellis.jvector.graph.NodeQueue;
 import io.github.jbellis.jvector.graph.NodesIterator;
 import io.github.jbellis.jvector.graph.similarity.ScoreFunction;
@@ -63,7 +63,7 @@ public void testBruteForceRowIdIteratorForEmptyPQAndTopKEqualsLimit()
         assertTrue(view.isClosed);
     }
 
-    private static class TestView implements GraphIndex.ScoringView
+    private static class TestView implements ImmutableGraphIndex.ScoringView
     {
         private boolean isClosed = false;
 
@@ -102,7 +102,7 @@ public int size()
         }
 
         @Override
-        public GraphIndex.NodeAtLevel entryNode()
+        public ImmutableGraphIndex.NodeAtLevel entryNode()
         {
             throw new UnsupportedOperationException();
         }
@@ -112,5 +112,11 @@ public Bits liveNodes()
         {
             throw new UnsupportedOperationException();
         }
+
+        @Override
+        public boolean contains(int i, int i1)
+        {
+            return false;
+        }
     }
 }