fix songbook compile issues & some warns

1 files changed, 2 insertions, 2 deletions

diff --git a/source/game/scripting/StarSongbookLuaBindings.cpp b/source/game/scripting/StarSongbookLuaBindings.cpp
index e2f70a3..7831ed6 100644
--- a/source/game/scripting/StarSongbookLuaBindings.cpp
+++ b/source/game/scripting/StarSongbookLuaBindings.cpp
@@ -10,8 +10,8 @@ LuaCallbacks LuaBindings::makeSongbookCallbacks(Songbook* songbook) {
   callbacks.registerCallbackWithSignature<void, String, Vec2F>("keepAlive", bind(mem_fn(&Songbook::keepAlive), songbook, _1, _2));
   callbacks.registerCallbackWithSignature<void>("stop", bind(mem_fn(&Songbook::stop), songbook));
   callbacks.registerCallbackWithSignature<bool>("active", bind(mem_fn(&Songbook::active), songbook));
-  callbacks.registerCallbackWithSignature<String>("band", bind(mem_fn(&Songbook::timeSource), songbook));
-  callbacks.registerCallbackWithSignature<String>("instrument", bind(mem_fn(&Songbook::instrument), songbook));
+  callbacks.registerCallbackWithSignature<Maybe<String>>("band", bind(mem_fn(&Songbook::timeSource), songbook));
+  callbacks.registerCallbackWithSignature<Maybe<String>>("instrument", bind(mem_fn(&Songbook::instrument), songbook));
   callbacks.registerCallbackWithSignature<bool>("instrumentPlaying", bind(mem_fn(&Songbook::instrumentPlaying), songbook));
   callbacks.registerCallbackWithSignature<Json>("song", bind(mem_fn(&Songbook::song), songbook));