diff --git a/lib/mixing_tab.dart b/lib/mixing_tab.dart
index 5c174d0..60c7bde 100644
--- a/lib/mixing_tab.dart
+++ b/lib/mixing_tab.dart
@@ -4,7 +4,7 @@ import 'package:gomix_flutter/mixer_state.dart' as mixer;
 
 class MixingTab extends StatefulWidget {
   final mixer.MixerState mixerState;
-  final Function sendAction;
+  final void Function(Map<String, Object> data) sendAction;
   const MixingTab(
       {super.key, required this.mixerState, required this.sendAction});