diff --git a/google-cloud-clients/google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/testing/FakeStorageRpc.java b/google-cloud-clients/google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/testing/FakeStorageRpc.java
index 07cb169511a4..515235cc5176 100644
--- a/google-cloud-clients/google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/testing/FakeStorageRpc.java
+++ b/google-cloud-clients/google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/testing/FakeStorageRpc.java
@@ -516,6 +516,7 @@ private static boolean processedAsFolder(
     fakeFolder.setName(folderName);
     fakeFolder.setBucket(so.getBucket());
     fakeFolder.setGeneration(so.getGeneration());
+    fakeFolder.set("isDirectory", true);
     folders.put(folderName, fakeFolder);
     return true;
   }