diff --git a/demo-cxx/demo.h b/demo-cxx/demo.h
index eea0af7..29a3ba1 100644
--- a/demo-cxx/demo.h
+++ b/demo-cxx/demo.h
@@ -20,7 +20,7 @@
 std::unique_ptr<ThingC> make_demo(::rust::Str appname);
 const std::string &get_name(const ThingC &thing);
 std::unique_ptr<std::vector<uint8_t>> do_thing(SharedThing state);
-JsonBlob get_jb(const ::rust::Vec<uint8_t>& vec);
+JsonBlob get_jb(const ::rust::Vec<uint8_t> &vec);
 
 } // namespace example
 } // namespace org