diff --git a/margfools b/margfools
index 5b70fd4..5fc52a9 100755
--- a/margfools
+++ b/margfools
@@ -97,8 +97,8 @@ if __name__ == '__main__':
         # keep signing whatever they send us
         while True:
             for name in ('AttachmentHashes', 'XmlHashes'):
-                if request.get(name) is not None:
-                    request[f'Signed{name}'] = [sign(e, args.key, pin, engine=args.engine) for e in request[name]]
+                if values := request.get(name, []):
+                    request[f'Signed{name}'] = [sign(v, args.key, pin, engine=args.engine) for v in values]
 
             r = session.put(f'{url}signatures/{request["SignatureRequestId"]}',
                 headers=headers | {'Content-Type': 'application/json; charset=utf-8'},