diff --git a/lib/generated/intl/messages_all.dart b/lib/generated/intl/messages_all.dart
index d261ca3..2c8e0a0 100644
--- a/lib/generated/intl/messages_all.dart
+++ b/lib/generated/intl/messages_all.dart
@@ -25,17 +25,17 @@ import 'messages_ru.dart' as messages_ru;
 import 'messages_tr.dart' as messages_tr;
 import 'messages_zh-Hans.dart' as messages_zh_hans;
 
-typedef LibraryLoader = Future<dynamic> Function();
+typedef Future<dynamic> LibraryLoader();
 Map<String, LibraryLoader> _deferredLibraries = {
-  'el': () => Future.value(null),
-  'en': () => Future.value(null),
-  'es': () => Future.value(null),
-  'fr': () => Future.value(null),
-  'it': () => Future.value(null),
-  'pt': () => Future.value(null),
-  'ru': () => Future.value(null),
-  'tr': () => Future.value(null),
-  'zh_Hans': () => Future.value(null),
+  'el': () => new Future.value(null),
+  'en': () => new Future.value(null),
+  'es': () => new Future.value(null),
+  'fr': () => new Future.value(null),
+  'it': () => new Future.value(null),
+  'pt': () => new Future.value(null),
+  'ru': () => new Future.value(null),
+  'tr': () => new Future.value(null),
+  'zh_Hans': () => new Future.value(null),
 };
 
 MessageLookupByLibrary? _findExact(String localeName) {
@@ -69,13 +69,13 @@ Future<bool> initializeMessages(String localeName) async {
       localeName, (locale) => _deferredLibraries[locale] != null,
       onFailure: (_) => null);
   if (availableLocale == null) {
-    return Future.value(false);
+    return new Future.value(false);
   }
   var lib = _deferredLibraries[availableLocale];
-  await (lib == null ? Future.value(false) : lib());
-  initializeInternalMessageLookup(() => CompositeMessageLookup());
+  await (lib == null ? new Future.value(false) : lib());
+  initializeInternalMessageLookup(() => new CompositeMessageLookup());
   messageLookup.addLocale(availableLocale, _findGeneratedMessagesFor);
-  return Future.value(true);
+  return new Future.value(true);
 }
 
 bool _messagesExistFor(String locale) {
diff --git a/lib/generated/intl/messages_el.dart b/lib/generated/intl/messages_el.dart
index 89ad283..e9dfe27 100644
--- a/lib/generated/intl/messages_el.dart
+++ b/lib/generated/intl/messages_el.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'el';
diff --git a/lib/generated/intl/messages_en.dart b/lib/generated/intl/messages_en.dart
index 16ab085..8fa8c8f 100644
--- a/lib/generated/intl/messages_en.dart
+++ b/lib/generated/intl/messages_en.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'en';
diff --git a/lib/generated/intl/messages_es.dart b/lib/generated/intl/messages_es.dart
index c7780c6..bb12442 100644
--- a/lib/generated/intl/messages_es.dart
+++ b/lib/generated/intl/messages_es.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'es';
diff --git a/lib/generated/intl/messages_fr.dart b/lib/generated/intl/messages_fr.dart
index 06505d0..616bf32 100644
--- a/lib/generated/intl/messages_fr.dart
+++ b/lib/generated/intl/messages_fr.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'fr';
diff --git a/lib/generated/intl/messages_it.dart b/lib/generated/intl/messages_it.dart
index 1826a0c..c4f0739 100644
--- a/lib/generated/intl/messages_it.dart
+++ b/lib/generated/intl/messages_it.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'it';
diff --git a/lib/generated/intl/messages_pt.dart b/lib/generated/intl/messages_pt.dart
index a5b6d0a..1591ad8 100644
--- a/lib/generated/intl/messages_pt.dart
+++ b/lib/generated/intl/messages_pt.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'pt';
diff --git a/lib/generated/intl/messages_ru.dart b/lib/generated/intl/messages_ru.dart
index e7c56ea..62b750c 100644
--- a/lib/generated/intl/messages_ru.dart
+++ b/lib/generated/intl/messages_ru.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'ru';
diff --git a/lib/generated/intl/messages_tr.dart b/lib/generated/intl/messages_tr.dart
index a2ea47c..98fe831 100644
--- a/lib/generated/intl/messages_tr.dart
+++ b/lib/generated/intl/messages_tr.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'tr';
diff --git a/lib/generated/intl/messages_zh-Hans.dart b/lib/generated/intl/messages_zh-Hans.dart
index 1e444d9..edfa328 100644
--- a/lib/generated/intl/messages_zh-Hans.dart
+++ b/lib/generated/intl/messages_zh-Hans.dart
@@ -13,10 +13,9 @@
 import 'package:intl/intl.dart';
 import 'package:intl/message_lookup_by_library.dart';
 
-final messages = MessageLookup();
+final messages = new MessageLookup();
 
-typedef MessageIfAbsent = String Function(
-    String messageStr, List<dynamic> args);
+typedef String MessageIfAbsent(String messageStr, List<dynamic> args);
 
 class MessageLookup extends MessageLookupByLibrary {
   String get localeName => 'zh_Hans';
diff --git a/lib/home/audioplayer.dart b/lib/home/audioplayer.dart
index b244154..f6bf307 100644
--- a/lib/home/audioplayer.dart
+++ b/lib/home/audioplayer.dart
@@ -54,11 +54,54 @@ class PlayerWidget extends StatelessWidget {
   PlayerWidget({this.playerKey, this.isPlayingPage = false});
   final GlobalKey<AudioPanelState>? playerKey;
   final bool isPlayingPage;
-  Widget _miniPanel(BuildContext context) {
-    var audio = Provider.of<AudioPlayerNotifier>(context, listen: false);
+
+  @override
+  Widget build(BuildContext context) {
+    return Selector<AudioPlayerNotifier, Tuple2<bool, PlayerHeight?>>(
+      selector: (_, audio) => Tuple2(audio.playerRunning, audio.playerHeight),
+      builder: (_, data, __) {
+        if (!data.item1) {
+          return Center();
+        } else {
+          final minHeight = kMinPlayerHeight[data.item2!.index];
+          final maxHeight = math.min(
+              kMaxPlayerHeight[data.item2!.index] as double,
+              context.height - 20);
+          return AudioPanel(
+            minHeight: minHeight,
+            maxHeight: maxHeight,
+            expandHeight: context.height - context.paddingTop - 20,
+            key: playerKey,
+            miniPanel: _MiniPanel(),
+            expandedPanel: ControlPanel(
+              maxHeight: maxHeight,
+              isPlayingPage: isPlayingPage,
+              onExpand: () {
+                playerKey!.currentState!.scrollToTop();
+              },
+              onClose: () {
+                playerKey!.currentState!.backToMini();
+              },
+            ),
+          );
+        }
+      },
+    );
+  }
+}
+
+class _MiniPanel extends StatelessWidget {
+  const _MiniPanel({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    final audio = Provider.of<AudioPlayerNotifier>(context, listen: false);
     final s = context.s;
+    final bgColor = audio.episode == null
+        ? context.primaryColor
+        : audio.episode!.cardColor(context);
     return Container(
-      color: context.primaryColor,
+      color: bgColor,
       height: 60,
       child:
           Column(mainAxisAlignment: MainAxisAlignment.start, children: <Widget>[
@@ -70,7 +113,7 @@ class PlayerWidget extends StatelessWidget {
               height: 2,
               child: LinearProgressIndicator(
                 value: data.item2,
-                backgroundColor: context.primaryColor,
+                backgroundColor: bgColor,
                 valueColor: AlwaysStoppedAnimation<Color>(c),
               ),
             );
@@ -223,40 +266,6 @@ class PlayerWidget extends StatelessWidget {
       ]),
     );
   }
-
-  @override
-  Widget build(BuildContext context) {
-    return Selector<AudioPlayerNotifier, Tuple2<bool, PlayerHeight?>>(
-      selector: (_, audio) => Tuple2(audio.playerRunning, audio.playerHeight),
-      builder: (_, data, __) {
-        if (!data.item1) {
-          return Center();
-        } else {
-          final minHeight = kMinPlayerHeight[data.item2!.index];
-          final maxHeight = math.min(
-              kMaxPlayerHeight[data.item2!.index] as double,
-              context.height - 20);
-          return AudioPanel(
-            minHeight: minHeight,
-            maxHeight: maxHeight,
-            expandHeight: context.height - context.paddingTop - 20,
-            key: playerKey,
-            miniPanel: _miniPanel(context),
-            expandedPanel: ControlPanel(
-              maxHeight: maxHeight,
-              isPlayingPage: isPlayingPage,
-              onExpand: () {
-                playerKey!.currentState!.scrollToTop();
-              },
-              onClose: () {
-                playerKey!.currentState!.backToMini();
-              },
-            ),
-          );
-        }
-      },
-    );
-  }
 }
 
 class LastPosition extends StatelessWidget {
@@ -285,9 +294,19 @@ class LastPosition extends StatelessWidget {
                   builder: (_, data, __) => TextButton(
                       child: Row(
                         children: [
-                          Icon(Icons.flash_on, size: 18),
+                          Icon(Icons.flash_on,
+                              size: 18,
+                              color: data!
+                                  ? context.accentColor
+                                  : context.textColor),
                           SizedBox(width: 5),
-                          Text(s.skipSilence),
+                          Text(
+                            s.skipSilence,
+                            style: TextStyle(
+                                color: data
+                                    ? context.accentColor
+                                    : context.textColor),
+                          ),
                         ],
                       ),
                       style: TextButton.styleFrom(
@@ -308,26 +327,38 @@ class LastPosition extends StatelessWidget {
               SizedBox(width: 10),
               Selector<AudioPlayerNotifier, bool?>(
                   selector: (_, audio) => audio.boostVolume,
-                  builder: (_, data, __) => FlatButton(
+                  builder: (_, data, __) => TextButton(
                       child: Row(
                         children: [
-                          Icon(Icons.volume_up, size: 18),
+                          Icon(Icons.volume_up,
+                              size: 18,
+                              color: data!
+                                  ? context.accentColor
+                                  : context.textColor),
                           SizedBox(width: 5),
-                          Text(s.boostVolume),
+                          Text(
+                            s.boostVolume,
+                            style: TextStyle(
+                                color: data
+                                    ? context.accentColor
+                                    : context.textColor),
+                          ),
                         ],
                       ),
-                      color: data! ? context.accentColor : Colors.transparent,
-                      padding: EdgeInsets.symmetric(horizontal: 10),
-                      shape: RoundedRectangleBorder(
-                          borderRadius: BorderRadius.circular(100.0),
-                          side: BorderSide(
-                              color: data
-                                  ? context.accentColor
-                                  : Theme.of(context)
-                                      .colorScheme
-                                      .onSurface
-                                      .withOpacity(0.12))),
-                      textColor: data ? Colors.white : null,
+                      style: TextButton.styleFrom(
+                        primary:
+                            data ? context.accentColor : Colors.transparent,
+                        shape: RoundedRectangleBorder(
+                            borderRadius: BorderRadius.circular(100.0),
+                            side: BorderSide(
+                                color: data
+                                    ? context.accentColor
+                                    : Theme.of(context)
+                                        .colorScheme
+                                        .onSurface
+                                        .withOpacity(0.12))),
+                        padding: EdgeInsets.symmetric(horizontal: 10),
+                      ),
                       onPressed: () =>
                           audio.setBoostVolume(boostVolume: !data))),
               SizedBox(width: 10),
@@ -1268,10 +1299,10 @@ class _ControlPanelState extends State<ControlPanel>
 
   @override
   Widget build(BuildContext context) {
-    var audio = Provider.of<AudioPlayerNotifier>(context, listen: false);
+    final audio = Provider.of<AudioPlayerNotifier>(context, listen: false);
     return LayoutBuilder(
       builder: (context, constraints) {
-        var height = constraints.maxHeight;
+        final height = constraints.maxHeight;
         return Container(
           color: context.primaryColor,
           height: 300,
@@ -1499,12 +1530,12 @@ class _ControlPanelState extends State<ControlPanel>
                             padding: EdgeInsets.only(left: 60, right: 60),
                             child: LayoutBuilder(
                               builder: (context, size) {
-                                var span = TextSpan(
+                                final span = TextSpan(
                                     text: title,
                                     style: TextStyle(
                                         fontWeight: FontWeight.bold,
                                         fontSize: 20));
-                                var tp = TextPainter(
+                                final tp = TextPainter(
                                     text: span,
                                     maxLines: 1,
                                     textDirection: TextDirection.ltr);
diff --git a/lib/home/home.dart b/lib/home/home.dart
index 60608ba..89c1fa3 100644
--- a/lib/home/home.dart
+++ b/lib/home/home.dart
@@ -58,6 +58,7 @@ class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
   final _androidAppRetain = MethodChannel("android_app_retain");
   var feature1OverflowMode = OverflowMode.clipContent;
   var feature1EnablePulsingAnimation = false;
+  double top = 0;
 
   @override
   void initState() {
@@ -87,7 +88,6 @@ class _HomeState extends State<Home> with SingleTickerProviderStateMixin {
     super.dispose();
   }
 
-  double top = 0;
   @override
   Widget build(BuildContext context) {
     final height = (context.width - 20) / 3 + 140;
diff --git a/lib/settings/play_setting.dart b/lib/settings/play_setting.dart
index adab1f8..ed0b104 100644
--- a/lib/settings/play_setting.dart
+++ b/lib/settings/play_setting.dart
@@ -180,7 +180,7 @@ class _PlaySettingState extends State<PlaySetting> {
                     EdgeInsets.only(left: 70.0, right: 20, bottom: 10, top: 10),
                 title: Text(s.settingsBoostVolume),
                 subtitle: Text(s.settingsBoostVolumeDes),
-                trailing: Selector<AudioPlayerNotifier, int?>(
+                trailing: Selector<AudioPlayerNotifier, int>(
                   selector: (_, audio) => audio.volumeGain,
                   builder: (_, volumeGain, __) => MyDropdownButton(
                       hint: Text(_volumeEffect(context, volumeGain)),
@@ -189,7 +189,7 @@ class _PlaySettingState extends State<PlaySetting> {
                       displayItemCount: 5,
                       isDense: true,
                       value: volumeGain,
-                      onChanged: (dynamic value) => audio.setVolumeGain = value,
+                      onChanged: (int value) => audio.setVolumeGain = value,
                       items: [2000, 3000, 4000].map<DropdownMenuItem<int>>((e) {
                         return DropdownMenuItem<int>(
                             value: e, child: Text(_volumeEffect(context, e)));
diff --git a/lib/state/audio_state.dart b/lib/state/audio_state.dart
index 37d7dcd..b9b422d 100644
--- a/lib/state/audio_state.dart
+++ b/lib/state/audio_state.dart
@@ -165,7 +165,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
   bool? _boostVolume;
 
   /// Boost volume gain.
-  int? _volumeGain;
+  late int _volumeGain;
 
   // ignore: prefer_final_fields
   bool _playerRunning = false;
@@ -241,7 +241,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
   PlayerHeight? get playerHeight => _playerHeight;
   bool? get skipSilence => _skipSilence;
   bool? get boostVolume => _boostVolume;
-  int? get volumeGain => _volumeGain;
+  int get volumeGain => _volumeGain;
 
   set setSwitchValue(double value) {
     _switchValue = value;
@@ -303,7 +303,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
         );
         await _playlist!.getPlaylist();
         if (state[1] != '') {
-          var episode = await _dbHelper.getRssItemWithUrl(state[1]);
+          final episode = await _dbHelper.getRssItemWithUrl(state[1]);
           if (episode != null &&
               ((!_playlist!.isQueue && _playlist!.contains(episode)) ||
                   (_playlist!.isQueue &&
@@ -476,18 +476,18 @@ class AudioPlayerNotifier extends ChangeNotifier {
     //Check auto sleep timer setting
     await _getAutoSleepTimer();
     if (_autoSleepTimer!) {
-      var startTime = await (_autoSleepTimerStartStorage.getInt(
-          defaultValue: 1380) as FutureOr<int>);
-      var endTime = await (_autoSleepTimerEndStorage.getInt(defaultValue: 360)
-          as FutureOr<int>);
-      var currentTime = DateTime.now().hour * 60 + DateTime.now().minute;
+      final startTime =
+          await (_autoSleepTimerStartStorage.getInt(defaultValue: 1380));
+      final endTime =
+          await (_autoSleepTimerEndStorage.getInt(defaultValue: 360));
+      final currentTime = DateTime.now().hour * 60 + DateTime.now().minute;
       if ((startTime > endTime &&
               (currentTime > startTime || currentTime < endTime)) ||
           ((startTime < endTime) &&
               (currentTime > startTime && currentTime < endTime))) {
-        var mode = await (_autoSleepTimerModeStorage.getInt() as FutureOr<int>);
+        final mode = await (_autoSleepTimerModeStorage.getInt());
         _sleepTimerMode = SleepTimerMode.values[mode];
-        var defaultTimer =
+        final defaultTimer =
             await _defaultSleepTimerStorage.getInt(defaultValue: 30);
         sleepTimer(defaultTimer);
       }
@@ -619,7 +619,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
 
   /// Queue management
   Future<void> addToPlaylist(EpisodeBrief episode) async {
-    var episodeNew = await (_dbHelper.getRssItemWithUrl(episode.enclosureUrl)
+    final episodeNew = await (_dbHelper.getRssItemWithUrl(episode.enclosureUrl)
         as FutureOr<EpisodeBrief>);
     if (episodeNew.isNew == 1) {
       await _dbHelper.removeEpisodeNewMark(episodeNew.enclosureUrl);
@@ -635,7 +635,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
   }
 
   Future<void> addToPlaylistAt(EpisodeBrief episode, int index) async {
-    var episodeNew = await (_dbHelper.getRssItemWithUrl(episode.enclosureUrl)
+    final episodeNew = await (_dbHelper.getRssItemWithUrl(episode.enclosureUrl)
         as FutureOr<EpisodeBrief>);
     if (episodeNew.isNew == 1) {
       await _dbHelper.removeEpisodeNewMark(episodeNew.enclosureUrl);
@@ -680,11 +680,11 @@ class AudioPlayerNotifier extends ChangeNotifier {
   }
 
   Future<int> delFromPlaylist(EpisodeBrief episode) async {
-    var episodeNew = await _dbHelper.getRssItemWithUrl(episode.enclosureUrl);
+    final episodeNew = await _dbHelper.getRssItemWithUrl(episode.enclosureUrl);
     if (playerRunning && _playlist!.isQueue) {
       await _audioHandler.removeQueueItem(episodeNew!.toMediaItem());
     }
-    var index = _queue.delFromPlaylist(episodeNew);
+    final index = _queue.delFromPlaylist(episodeNew);
     if (index == 0) {
       _lastPosition = 0;
       await _positionStorage.saveInt(0);
@@ -697,7 +697,7 @@ class AudioPlayerNotifier extends ChangeNotifier {
     if (newIndex > oldIndex) {
       newIndex -= 1;
     }
-    var episode = _queue.episodes[oldIndex]!;
+    final episode = _queue.episodes[oldIndex]!;
     _queue.addToPlayListAt(episode, newIndex);
     updatePlaylist(_queue, updateEpisodes: false);
     if (playerRunning && _playlist!.name == 'Queue') {
@@ -910,13 +910,13 @@ class AudioPlayerNotifier extends ChangeNotifier {
   set setVolumeGain(int volumeGain) {
     _volumeGain = volumeGain;
     if (_playerRunning && _boostVolume!) {
-      setBoostVolume(boostVolume: _boostVolume, gain: _volumeGain);
+      setBoostVolume(boostVolume: _boostVolume!, gain: _volumeGain);
     }
     notifyListeners();
     _volumeGainStorage.saveInt(volumeGain);
   }
 
-  Future<void> setBoostVolume({required bool? boostVolume, int? gain}) async {
+  Future<void> setBoostVolume({required bool boostVolume, int? gain}) async {
     await _audioHandler.customAction(
         'setBoostVolume', {'boostVolume': boostVolume, 'gain': _volumeGain});
     _boostVolume = boostVolume;
@@ -1297,7 +1297,7 @@ class CustomAudioHandler extends BaseAudioHandler
 
   Future _setBoostVolume(bool enabled, int gain) async {
     await _loudnessEnhancer.setEnabled(enabled);
-    await _loudnessEnhancer.setTargetGain(1.5);
+    await _loudnessEnhancer.setTargetGain(gain / 2000);
   }
 
   List<MediaControl> _getControls(int? index) {
diff --git a/lib/widgets/custom_dropdown.dart b/lib/widgets/custom_dropdown.dart
index 0157353..c3b1505 100644
--- a/lib/widgets/custom_dropdown.dart
+++ b/lib/widgets/custom_dropdown.dart
@@ -150,7 +150,7 @@ class _DropdownMenuItemButtonState<T>
 
     Navigator.pop(
       context,
-      _DropdownRouteResult<T?>(dropdownMenuItem.value),
+      _DropdownRouteResult<T>(dropdownMenuItem.value!),
     );
   }