--- a/qmlfrontend/engine_interface.h	Fri Dec 07 13:56:45 2018 +0100
+++ b/qmlfrontend/engine_interface.h	Fri Dec 07 14:30:35 2018 +0100
@@ -22,6 +22,7 @@
 typedef EngineInstance* start_engine_t();
 typedef void generate_preview_t(EngineInstance* engine_state,
                                 PreviewInfo* preview);
+typedef void dispose_preview_t(EngineInstance* engine_state);
 typedef void cleanup_t(EngineInstance* engine_state);
 
 typedef void send_ipc_t(EngineInstance* engine_state, uint8_t* buf,