diff --git a/src/StreamingParser.php b/src/StreamingParser.php
index e7d6769..6bcc29b 100644
--- a/src/StreamingParser.php
+++ b/src/StreamingParser.php
@@ -30,7 +30,7 @@ public function parseForm(Request $request): ConcurrentIterator
     {
         $boundary = parseContentBoundary($request->getHeader('content-type') ?? '');
         if ($boundary === null) {
-            return Pipeline::fromIterable([]);
+            return Pipeline::fromIterable([])->getIterator();
         }
 
         $source = new Queue();