diff --git a/app/Helpers/Attachments/AttachmentHelper.php b/app/Helpers/Attachments/AttachmentHelper.php
index d442d46137..b988220f21 100644
--- a/app/Helpers/Attachments/AttachmentHelper.php
+++ b/app/Helpers/Attachments/AttachmentHelper.php
@@ -171,6 +171,7 @@ class AttachmentHelper implements AttachmentHelperInterface
         $allowedMime = config('firefly.allowedMimes');
         if (!in_array($mime, $allowedMime, true)) {
             Log::error(sprintf('Mime type %s is not allowed for API file upload.', $mime));
+            fclose($resource);
 
             return false;
         }