diff --git a/src/allmydata/web/unlinked.py b/src/allmydata/web/unlinked.py
index 2c7be6f30..a44e7fcb5 100644
--- a/src/allmydata/web/unlinked.py
+++ b/src/allmydata/web/unlinked.py
@@ -160,7 +160,7 @@ def POSTUnlinkedCreateDirectory(req, client):
     mt = None
     if file_format:
         mt = get_mutable_type(file_format)
-    d = client.create_dirnode(version=mt)
+    d = client.create_dirnode(version=mt, unique_keypair=get_keypair(req))
     redirect = get_arg(req, "redirect_to_result", "false")
     if boolean_of_arg(redirect):
         def _then_redir(res):