diff --git a/solr/core/src/test/org/apache/solr/handler/IndexFetcherPacketProtocolTest.java b/solr/core/src/test/org/apache/solr/handler/IndexFetcherPacketProtocolTest.java
index e9d639f1ab37..36d47427a4f4 100644
--- a/solr/core/src/test/org/apache/solr/handler/IndexFetcherPacketProtocolTest.java
+++ b/solr/core/src/test/org/apache/solr/handler/IndexFetcherPacketProtocolTest.java
@@ -227,10 +227,13 @@ private byte[] createDeterministicContent(int size) {
   /** Writes file content to a directory and serializes it using the replication packet protocol. */
   private byte[] serializeFileToPacketStream(byte[] content, String fileName) throws Exception {
     DirectoryFactory directoryFactory = h.getCore().getDirectoryFactory();
+    // Use the same REPLICATION DirContext that the sender (DirectoryFileStream) uses to read the
+    // file, so the write and the read target the same (unwrapped) delegate Directory. For
+    // REPLICATION/BACKUP, CachingDirectoryFactory.filterDirectory() unwraps to the raw delegate.
     Directory dir =
         directoryFactory.get(
             h.getCore().getNewIndexDir(),
-            DirectoryFactory.DirContext.DEFAULT,
+            DirectoryFactory.DirContext.REPLICATION,
             h.getCore().getSolrConfig().indexConfig.lockType);
 
     try {