diff --git a/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java b/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
index e3edb34451a0..c94317fe48c6 100644
--- a/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
+++ b/gluten-core/src/main/java/org/apache/gluten/hash/ConsistentHash.java
@@ -162,7 +162,8 @@ public Set<T> getNodes() {
   public Set<Partition<T>> getPartition(T node) {
     lock.readLock().lock();
     try {
-      return nodes.get(node);
+      Set<Partition<T>> partitions = nodes.get(node);
+      return partitions == null ? null : Collections.unmodifiableSet(partitions);
     } finally {
       lock.readLock().unlock();
     }