diff --git a/example/pubspec.lock b/example/pubspec.lock
index 8825e8e..5085c21 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0"
   bloc:
     dependency: transitive
     description:
@@ -21,7 +21,7 @@ packages:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   bubble:
     dependency: "direct main"
     description:
@@ -35,28 +35,28 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -70,7 +70,7 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -82,7 +82,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.1.6"
+    version: "0.2.0-nullsafety.0"
   flutter_bloc:
     dependency: "direct main"
     description:
@@ -115,14 +115,14 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   nested:
     dependency: transitive
     description:
@@ -136,7 +136,7 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0"
   pedantic:
     dependency: "direct dev"
     description:
@@ -176,56 +176,56 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
-  flutter: ">=1.20.0 <2.0.0"
+  dart: ">=2.12.0-29.10.beta <3.0.0"
+  flutter: ">=1.20.0"
diff --git a/lib/src/android_config.dart b/lib/src/android_config.dart
index e54e855..3f92054 100644
--- a/lib/src/android_config.dart
+++ b/lib/src/android_config.dart
@@ -1,5 +1,3 @@
-import 'package:flutter/foundation.dart';
-
 /// Represents the importance of an android notification as described
 /// under https://developer.android.com/training/notify-user/channels#importance.
 enum AndroidNotificationImportance {
@@ -19,8 +17,7 @@ class AndroidResource {
   // Optional default resource type to find, if "type/" is not included in the name. Can be null to require an explicit type.
   final String defType;
 
-  const AndroidResource({@required this.name, this.defType = 'drawable'})
-      : assert(name != null);
+  const AndroidResource({required this.name, this.defType = 'drawable'});
 }
 
 /// Android configuration for the [FlutterBackground] plugin.
@@ -51,8 +48,5 @@ class FlutterBackgroundAndroidConfig {
       this.notificationText = 'Notification text',
       this.notificationImportance = AndroidNotificationImportance.Default,
       this.notificationIcon =
-          const AndroidResource(name: 'ic_launcher', defType: 'mipmap')})
-      : assert(notificationTitle != null),
-        assert(notificationText != null),
-        assert(notificationImportance != null);
+          const AndroidResource(name: 'ic_launcher', defType: 'mipmap')});
 }
diff --git a/lib/src/flutter_background.dart b/lib/src/flutter_background.dart
index 363e178..8bfd43d 100644
--- a/lib/src/flutter_background.dart
+++ b/lib/src/flutter_background.dart
@@ -18,14 +18,14 @@ class FlutterBackground {
   static Future<bool> initialize(
       {FlutterBackgroundAndroidConfig androidConfig =
           const FlutterBackgroundAndroidConfig()}) async {
-    _isInitialized = await _channel.invokeMethod('initialize', {
+    _isInitialized = await _channel.invokeMethod<bool>('initialize', {
       'android.notificationTitle': androidConfig.notificationTitle,
       'android.notificationText': androidConfig.notificationText,
       'android.notificationImportance': _androidNotificationImportanceToInt(
           androidConfig.notificationImportance),
       'android.notificationIconName': androidConfig.notificationIcon.name,
       'android.notificationIconDefType': androidConfig.notificationIcon.defType,
-    });
+    }) == true;
     return _isInitialized;
   }
 
@@ -34,7 +34,7 @@ class FlutterBackground {
   /// Returns true, if the user has granted the permission, otherwise false.
   /// May throw a [PlatformException].
   static Future<bool> get hasPermissions async {
-    return await _channel.invokeMethod('hasPermissions') as bool;
+    return await _channel.invokeMethod<bool>('hasPermissions') == true;
   }
 
   /// Enables the execution of the flutter app in the background.
@@ -46,9 +46,9 @@ class FlutterBackground {
   static Future<bool> enableBackgroundExecution() async {
     if (_isInitialized) {
       final success =
-          await _channel.invokeMethod('enableBackgroundExecution') as bool;
+          await _channel.invokeMethod<bool>('enableBackgroundExecution');
       _isBackgroundExecutionEnabled = true;
-      return success;
+      return success == true;
     } else {
       throw Exception(
           'FlutterBackground plugin must be initialized before calling enableBackgroundExecution()');
@@ -61,11 +61,11 @@ class FlutterBackground {
   /// Returns true if successful, otherwise false.
   /// Throws an [Exception] if the plugin is not initialized by calling [FlutterBackground.initialize()] first.
   /// May throw a [PlatformException].
-  static Future<void> disableBackgroundExecution() async {
+  static Future<bool> disableBackgroundExecution() async {
     if (_isInitialized) {
-      final success = await _channel.invokeMethod('disableBackgroundExecution');
+      final success = await _channel.invokeMethod<bool>('disableBackgroundExecution');
       _isBackgroundExecutionEnabled = false;
-      return success;
+      return success == true;
     } else {
       throw Exception(
           'FlutterBackground plugin must be initialized before calling disableBackgroundExecution()');
diff --git a/pubspec.lock b/pubspec.lock
index c731f2a..90a3fb2 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,49 +7,49 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -66,21 +66,21 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0"
   pedantic:
     dependency: "direct dev"
     description:
@@ -99,56 +99,56 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
-  flutter: ">=1.20.0 <2.0.0"
+  dart: ">=2.12.0-29.10.beta <3.0.0"
+  flutter: ">=1.20.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 18ccc57..14cb54a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: flutter_background
 description: A plugin to keep flutter apps running in the background by using foreground service, wake lock and disabling battery optimizations
-version: 0.1.6
+version: 0.2.0-nullsafety.0
 repository: https://github.com/JulianAssmann/flutter_background
 homepage: https://julianassmann.de/
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0-29.10.beta <3.0.0"
   flutter: ">=1.20.0 <2.0.0"
 
 dependencies: