diff --git a/lib/aeyrium_sensor.dart b/lib/aeyrium_sensor.dart
index 7d133e5..a213574 100644
--- a/lib/aeyrium_sensor.dart
+++ b/lib/aeyrium_sensor.dart
@@ -21,12 +21,12 @@ class SensorEvent {
 }
 
 class AeyriumSensor {
-  static Stream<SensorEvent> _sensorEvents;
+  static Stream<SensorEvent>? _sensorEvents;
 
   AeyriumSensor._();
 
   /// A broadcast stream of events from the device rotation sensor.
-  static Stream<SensorEvent> get sensorEvents {
+  static Stream<SensorEvent>? get sensorEvents {
     if (_sensorEvents == null) {
       _sensorEvents = _sensorEventChannel
           .receiveBroadcastStream()
diff --git a/pubspec.lock b/pubspec.lock
index f9c75f5..e8f85ea 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1,69 +1,111 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "19.0.0"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.36.3"
+    version: "1.3.0"
   args:
     dependency: transitive
     description:
       name: args
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.0"
+    version: "2.0.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.0"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.2.0"
+  cli_util:
+    dependency: transitive
+    description:
+      name: cli_util
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.0"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
   convert:
     dependency: transitive
     description:
       name: convert
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.2"
+    version: "3.0.0"
+  coverage:
+    dependency: transitive
+    description:
+      name: coverage
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.2"
   crypto:
     dependency: transitive
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.6"
-  csslib:
+    version: "3.0.0"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
+  file:
     dependency: transitive
     description:
-      name: csslib
+      name: file
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.5"
+    version: "6.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -74,195 +116,139 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  front_end:
-    dependency: transitive
-    description:
-      name: front_end
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.1.18"
   glob:
     dependency: transitive
     description:
       name: glob
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.7"
-  html:
-    dependency: transitive
-    description:
-      name: html
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.14.0+2"
-  http:
-    dependency: transitive
-    description:
-      name: http
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.11.3+17"
+    version: "2.0.0"
   http_multi_server:
     dependency: transitive
     description:
       name: http_multi_server
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.5"
+    version: "3.0.0"
   http_parser:
     dependency: transitive
     description:
       name: http_parser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.3"
+    version: "4.0.0"
   io:
     dependency: transitive
     description:
       name: io
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.3"
+    version: "1.0.0"
   js:
     dependency: transitive
     description:
       name: js
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.6.1+1"
-  json_rpc_2:
-    dependency: transitive
-    description:
-      name: json_rpc_2
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
-  kernel:
-    dependency: transitive
-    description:
-      name: kernel
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.3.18"
+    version: "0.6.3"
   logging:
     dependency: transitive
     description:
       name: logging
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.11.3+2"
+    version: "1.0.0"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.5"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   mime:
     dependency: transitive
     description:
       name: mime
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.6+2"
-  multi_server_socket:
-    dependency: transitive
-    description:
-      name: multi_server_socket
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.2"
+    version: "1.0.0"
   node_preamble:
     dependency: transitive
     description:
       name: node_preamble
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.4"
+    version: "1.4.13"
   package_config:
     dependency: transitive
     description:
       name: package_config
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
-  package_resolver:
-    dependency: transitive
-    description:
-      name: package_resolver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.4"
+    version: "2.0.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.2"
+    version: "1.8.0"
   pedantic:
     dependency: transitive
     description:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.11.0"
   pool:
     dependency: transitive
     description:
       name: pool
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.6"
+    version: "1.5.0"
   pub_semver:
     dependency: transitive
     description:
       name: pub_semver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.3"
+    version: "2.0.0"
   shelf:
     dependency: transitive
     description:
       name: shelf
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.7.5"
+    version: "1.1.0"
   shelf_packages_handler:
     dependency: transitive
     description:
       name: shelf_packages_handler
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "3.0.0"
   shelf_static:
     dependency: transitive
     description:
       name: shelf_static
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.8"
+    version: "1.0.0"
   shelf_web_socket:
     dependency: transitive
     description:
       name: shelf_web_socket
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.3"
+    version: "1.0.1"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -274,111 +260,118 @@ packages:
       name: source_map_stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.5"
+    version: "2.1.0"
   source_maps:
     dependency: transitive
     description:
       name: source_maps
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.10.7"
+    version: "0.10.10"
   source_span:
     dependency: transitive
     description:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test:
     dependency: "direct dev"
     description:
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.3"
+    version: "1.16.5"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.5"
+    version: "0.2.19"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.5"
+    version: "0.3.15"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
-  vm_service_client:
+    version: "2.1.0"
+  vm_service:
     dependency: transitive
     description:
-      name: vm_service_client
+      name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.6+2"
+    version: "6.1.0+1"
   watcher:
     dependency: transitive
     description:
       name: watcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.7+10"
+    version: "1.0.0"
   web_socket_channel:
     dependency: transitive
     description:
       name: web_socket_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.13"
+    version: "2.0.0"
+  webkit_inspection_protocol:
+    dependency: transitive
+    description:
+      name: webkit_inspection_protocol
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
   yaml:
     dependency: transitive
     description:
       name: yaml
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.15"
+    version: "3.1.0"
 sdks:
-  dart: ">=2.2.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index ebf5a8d..5b55f7b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -8,14 +8,14 @@ homepage: https://aeyrium.com/
 repository: https://github.com/aeyrium/aeyrium-sensor
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
 
 dev_dependencies:
-  test: ^1.3.0
+  test: ^1.16.5
   flutter_test:
     sdk: flutter
 
diff --git a/test/aeyrium_sensor_test.dart b/test/aeyrium_sensor_test.dart
index e21b466..40f675b 100644
--- a/test/aeyrium_sensor_test.dart
+++ b/test/aeyrium_sensor_test.dart
@@ -15,16 +15,16 @@ void main() {
       BinaryMessages.handlePlatformMessage(
         channelName,
         event,
-        (ByteData reply) {},
+        (ByteData? reply) {},
       );
     }
 
     bool isCanceled = false;
-    BinaryMessages.setMockMessageHandler(channelName, (ByteData message) async {
+    BinaryMessages.setMockMessageHandler(channelName,
+        (ByteData? message) async {
       final MethodCall methodCall = standardMethod.decodeMethodCall(message);
       if (methodCall.method == 'listen') {
         emitEvent(standardMethod.encodeSuccessEnvelope(sensorData));
-        emitEvent(null);
         return standardMethod.encodeSuccessEnvelope(null);
       } else if (methodCall.method == 'cancel') {
         isCanceled = true;
@@ -34,7 +34,7 @@ void main() {
       }
     });
 
-    final SensorEvent event = await AeyriumSensor.sensorEvents.first;
+    final SensorEvent event = await AeyriumSensor.sensorEvents!.first;
     expect(event.pitch, 1.0);
     expect(event.roll, 2.0);