diff --git a/lib/dart/README.md b/lib/dart/README.md
index 2be168b..4c30291 100644
--- a/lib/dart/README.md
+++ b/lib/dart/README.md
@@ -23,4 +23,4 @@
 Using Thrift with Dart
 ====================
 
-Dart 1.12.0 or newer is required
+Dart 1.24.3 or newer is required
diff --git a/lib/dart/lib/src/browser/t_web_socket.dart b/lib/dart/lib/src/browser/t_web_socket.dart
index 17693b3..dac9ffd 100644
--- a/lib/dart/lib/src/browser/t_web_socket.dart
+++ b/lib/dart/lib/src/browser/t_web_socket.dart
@@ -18,7 +18,7 @@
 library thrift.src.browser;
 
 import 'dart:async';
-import 'dart:convert' show BASE64;
+import 'package:dart2_constant/convert.dart' show base64;
 import 'dart:html' show CloseEvent;
 import 'dart:html' show Event;
 import 'dart:html' show MessageEvent;
@@ -90,7 +90,7 @@
   void _sendRequests() {
     while (isOpen && _requests.isNotEmpty) {
       Uint8List data = _requests.removeAt(0);
-      _socket.sendString(BASE64.encode(data));
+      _socket.sendString(base64.encode(data));
     }
   }
 
@@ -113,8 +113,7 @@
 
   void _onMessage(MessageEvent message) {
     try {
-      Uint8List data =
-          new Uint8List.fromList(BASE64.decode(message.data));
+      Uint8List data = new Uint8List.fromList(base64.decode(message.data));
       _onMessageController.add(data);
     } on FormatException catch (_) {
       var error = new TProtocolError(TProtocolErrorType.INVALID_DATA,
diff --git a/lib/dart/lib/src/console/t_web_socket.dart b/lib/dart/lib/src/console/t_web_socket.dart
index 4ed7284..c938a96 100644
--- a/lib/dart/lib/src/console/t_web_socket.dart
+++ b/lib/dart/lib/src/console/t_web_socket.dart
@@ -18,7 +18,7 @@
 library thrift.src.console.t_web_socket;
 
 import 'dart:async';
-import 'dart:convert' show BASE64;
+import 'package:dart2_constant/convert.dart' show base64;
 import 'dart:io';
 import 'dart:typed_data' show Uint8List;
 
@@ -67,13 +67,12 @@
   }
 
   void send(Uint8List data) {
-    _socket.add(BASE64.encode(data));
+    _socket.add(base64.encode(data));
   }
 
   void _onMessage(String message) {
     try {
-      Uint8List data =
-          new Uint8List.fromList(BASE64.decode(message));
+      Uint8List data = new Uint8List.fromList(base64.decode(message));
       _onMessageController.add(data);
     } on FormatException catch (_) {
       var error = new TProtocolError(TProtocolErrorType.INVALID_DATA,
diff --git a/lib/dart/lib/src/protocol/t_compact_protocol.dart b/lib/dart/lib/src/protocol/t_compact_protocol.dart
index 72d7641..ee8094f 100644
--- a/lib/dart/lib/src/protocol/t_compact_protocol.dart
+++ b/lib/dart/lib/src/protocol/t_compact_protocol.dart
@@ -187,7 +187,7 @@
 
   void writeDouble(double d) {
     if (d == null) d = 0.0;
-    tempBD.setFloat64(0, d, Endianness.LITTLE_ENDIAN);
+    tempBD.setFloat64(0, d, Endianness.little);
     transport.write(tempBD.buffer.asUint8List(), 0, 8);
   }
 
@@ -364,7 +364,7 @@
 
   double readDouble() {
     transport.readAll(tempList, 0, 8);
-    return tempList.buffer.asByteData().getFloat64(0, Endianness.LITTLE_ENDIAN);
+    return tempList.buffer.asByteData().getFloat64(0, Endianness.little);
   }
 
   String readString() {
diff --git a/lib/dart/lib/src/protocol/t_json_protocol.dart b/lib/dart/lib/src/protocol/t_json_protocol.dart
index 7fbb7c4..180568d 100644
--- a/lib/dart/lib/src/protocol/t_json_protocol.dart
+++ b/lib/dart/lib/src/protocol/t_json_protocol.dart
@@ -155,8 +155,8 @@
     _context.write();
     transport.writeAll(_Constants.QUOTE_BYTES);
 
-    String base64 = BASE64.encode(bytes);
-    transport.writeAll(utf8Codec.encode(base64));
+    String base64text = base64.encode(bytes);
+    transport.writeAll(utf8Codec.encode(base64text));
 
     transport.writeAll(_Constants.QUOTE_BYTES);
   }
@@ -421,9 +421,9 @@
   Uint8List _readJsonBase64() {
     // convert UTF-8 bytes of a Base 64 encoded string to binary bytes
     Uint8List base64Bytes = _readJsonString();
-    String base64 = utf8Codec.decode(base64Bytes);
+    String base64text = utf8Codec.decode(base64Bytes);
 
-    return new Uint8List.fromList(BASE64.decode(base64));
+    return new Uint8List.fromList(base64.decode(base64text));
   }
 
   void _readJsonObjectStart() {
diff --git a/lib/dart/lib/src/serializer/t_deserializer.dart b/lib/dart/lib/src/serializer/t_deserializer.dart
index ed1d139..aefbee2 100644
--- a/lib/dart/lib/src/serializer/t_deserializer.dart
+++ b/lib/dart/lib/src/serializer/t_deserializer.dart
@@ -26,7 +26,7 @@
     this.transport = new TBufferedTransport();
     
     if (protocolFactory == null) {
-        protocolFactory = new TBinaryProtocolFactory();
+      protocolFactory = new TBinaryProtocolFactory();
     }
     
     this.protocol = protocolFactory.getProtocol(this.transport);
@@ -41,8 +41,8 @@
   }
 
   void readString(TBase base, String data) {
-    transport.writeAll(BASE64.decode(data));
     
+    transport.writeAll(base64.decode(data));
     transport.flush();
 
     base.read(protocol);
diff --git a/lib/dart/lib/src/serializer/t_serializer.dart b/lib/dart/lib/src/serializer/t_serializer.dart
index 20ddb6d..feec822 100644
--- a/lib/dart/lib/src/serializer/t_serializer.dart
+++ b/lib/dart/lib/src/serializer/t_serializer.dart
@@ -43,6 +43,6 @@
     
     Uint8List bytes = transport.consumeWriteBuffer();
     
-    return BASE64.encode(bytes);
+    return base64.encode(bytes);
   }
 }
diff --git a/lib/dart/lib/src/transport/t_http_transport.dart b/lib/dart/lib/src/transport/t_http_transport.dart
index aa78e9c..630213f 100644
--- a/lib/dart/lib/src/transport/t_http_transport.dart
+++ b/lib/dart/lib/src/transport/t_http_transport.dart
@@ -44,7 +44,7 @@
   }
 
   Future flush() {
-    var requestBody = BASE64.encode(consumeWriteBuffer());
+    var requestBody = base64.encode(consumeWriteBuffer());
 
     // Use a sync completer to ensure that the buffer can be read immediately
     // after the read buffer is set, and avoid a race condition where another
@@ -56,8 +56,7 @@
         .then((response) {
       Uint8List data;
       try {
-        data = new Uint8List.fromList(
-            BASE64.decode(response.body));
+        data = new Uint8List.fromList(base64.decode(response.body));
       } on FormatException catch (_) {
         throw new TProtocolError(TProtocolErrorType.INVALID_DATA,
             "Expected a Base 64 encoded string.");
diff --git a/lib/dart/lib/thrift.dart b/lib/dart/lib/thrift.dart
index 3d9bb01..c429d77 100644
--- a/lib/dart/lib/thrift.dart
+++ b/lib/dart/lib/thrift.dart
@@ -19,11 +19,12 @@
 
 import 'dart:async';
 import 'dart:collection';
-import 'dart:convert' show Utf8Codec, BASE64;
+import 'dart:convert' show Utf8Codec;
 import 'dart:typed_data' show ByteData;
-import 'dart:typed_data' show Endianness;
 import 'dart:typed_data' show Uint8List;
 
+import 'package:dart2_constant/convert.dart' show base64;
+import 'package:dart2_constant/typed_data.dart' show Endianness;
 import 'package:fixnum/fixnum.dart';
 import 'package:http/http.dart' show Client;
 import 'package:logging/logging.dart';
diff --git a/lib/dart/pubspec.yaml b/lib/dart/pubspec.yaml
index fdc4a0d..ded0269 100644
--- a/lib/dart/pubspec.yaml
+++ b/lib/dart/pubspec.yaml
@@ -24,20 +24,15 @@
 documentation: http://thrift.apache.org
 
 environment:
-  sdk: ">=1.13.0 <2.0.0"
+  sdk: ">=1.24.3 <3.0.0"
 
 dependencies:
+  dart2_constant: ^1.0.0
   fixnum: ^0.10.2
   http: ^0.11.3
   logging: ^0.11.0
 
 dev_dependencies:
-  # test
-  mockito: ^1.0.0
-  test: ^0.12.0
-
-  # dart_dev - https://github.com/Workiva/dart_dev
-  dart_dev: ^1.5.0
-  coverage: ^0.7.3
-  dart_style: ">=0.2.4 <0.3.0"
-  dartdoc: ^0.9.0
+  dart_dev: ^2.0.0
+  mockito: ">=2.2.2 <4.0.0"
+  test: ">=0.12.30 <2.0.0"
diff --git a/lib/dart/test/protocol/t_protocol_test.dart b/lib/dart/test/protocol/t_protocol_test.dart
index 0e6cde5..dc63dbb 100644
--- a/lib/dart/test/protocol/t_protocol_test.dart
+++ b/lib/dart/test/protocol/t_protocol_test.dart
@@ -18,9 +18,9 @@
 library thrift.test.transport.t_json_protocol_test;
 
 import 'dart:async';
-import 'dart:convert' show UTF8;
 import 'dart:typed_data' show Uint8List;
 
+import 'package:dart2_constant/convert.dart' show utf8;
 import 'package:test/test.dart';
 import 'package:thrift/thrift.dart';
 
@@ -362,7 +362,7 @@
            UTF-8:  0xF0 0x9D 0x84 0x9E
            UTF-16: 0xD834 0xDD1E
        */
-      var buffer = UTF8.encode(r'"\u0001\u0e01 \ud834\udd1e"');
+      var buffer = utf8.encode(r'"\u0001\u0e01 \ud834\udd1e"');
       var transport = new TBufferedTransport();
       transport.writeAll(buffer);
 
@@ -372,7 +372,7 @@
 
       var subject = protocol.readString();
       expect(subject,
-          UTF8.decode([0x01, 0xE0, 0xB8, 0x81, 0x20, 0xF0, 0x9D, 0x84, 0x9E]));
+          utf8.decode([0x01, 0xE0, 0xB8, 0x81, 0x20, 0xF0, 0x9D, 0x84, 0x9E]));
     });
 
     group('shared tests', sharedTests);
diff --git a/lib/dart/test/transport/t_framed_transport_test.dart b/lib/dart/test/transport/t_framed_transport_test.dart
index e072e68..7ab4905 100644
--- a/lib/dart/test/transport/t_framed_transport_test.dart
+++ b/lib/dart/test/transport/t_framed_transport_test.dart
@@ -18,9 +18,9 @@
 library thrift.test.transport.t_framed_transport_test;
 
 import 'dart:async';
-import 'dart:convert';
 import 'dart:typed_data' show Uint8List;
 
+import 'package:dart2_constant/convert.dart' show utf8;
 import 'package:test/test.dart';
 import 'package:thrift/thrift.dart';
 
@@ -66,14 +66,14 @@
       expectNoReadableBytes();
 
       // write first batch of body
-      socket.messageController.add(new Uint8List.fromList(UTF8.encode("He")));
+      socket.messageController.add(new Uint8List.fromList(utf8.encode("He")));
 
       // you shouldn't be able to get any bytes from the read,
       // because the frame has been consumed internally
       expectNoReadableBytes();
 
       // write second batch of body
-      socket.messageController.add(new Uint8List.fromList(UTF8.encode("llo!")));
+      socket.messageController.add(new Uint8List.fromList(utf8.encode("llo!")));
 
       // have to wait for the flush to complete,
       // because it's only then that the frame is available for reading
@@ -83,7 +83,7 @@
       // at this point the frame is complete, so we expect the read to complete
       readBytes = transport.read(readBuffer, 0, readBuffer.lengthInBytes);
       expect(readBytes, 6);
-      expect(readBuffer.sublist(0, 6), UTF8.encode("Hello!"));
+      expect(readBuffer.sublist(0, 6), utf8.encode("Hello!"));
     });
 
     test('Test transport reads messages where header is sent in pieces '
@@ -112,14 +112,14 @@
       readBytes = expectNoReadableBytes();
 
       // write first batch of body
-      socket.messageController.add(new Uint8List.fromList(UTF8.encode("H")));
+      socket.messageController.add(new Uint8List.fromList(utf8.encode("H")));
 
       // you shouldn't be able to get any bytes from the read,
       // because the frame has been consumed internally
       expectNoReadableBytes();
 
       // write second batch of body
-      socket.messageController.add(new Uint8List.fromList(UTF8.encode("i!")));
+      socket.messageController.add(new Uint8List.fromList(utf8.encode("i!")));
 
       // have to wait for the flush to complete,
       // because it's only then that the frame is available for reading
@@ -129,7 +129,7 @@
       // at this point the frame is complete, so we expect the read to complete
       readBytes = transport.read(readBuffer, 0, readBuffer.lengthInBytes);
       expect(readBytes, 3);
-      expect(readBuffer.sublist(0, 3), UTF8.encode("Hi!"));
+      expect(readBuffer.sublist(0, 3), utf8.encode("Hi!"));
     });
   });
 }
diff --git a/lib/dart/test/transport/t_http_transport_test.dart b/lib/dart/test/transport/t_http_transport_test.dart
index 66f3d05..03ccede 100644
--- a/lib/dart/test/transport/t_http_transport_test.dart
+++ b/lib/dart/test/transport/t_http_transport_test.dart
@@ -19,9 +19,10 @@
 
 import 'dart:async';
 import 'dart:convert' show Encoding;
-import 'dart:convert' show Utf8Codec, BASE64;
+import 'dart:convert' show Utf8Codec;
 import 'dart:typed_data' show Uint8List;
 
+import 'package:dart2_constant/convert.dart' show base64;
 import 'package:http/http.dart' show BaseRequest;
 import 'package:http/http.dart' show Client;
 import 'package:http/http.dart' show Response;
@@ -52,15 +53,14 @@
 
       expect(client.postRequest, isNotEmpty);
 
-      var requestText =
-          utf8Codec.decode(BASE64.decode(client.postRequest));
+      var requestText = utf8Codec.decode(base64.decode(client.postRequest));
       expect(requestText, expectedText);
     });
 
     test('Test transport receives response', () async {
       var expectedText = 'my response';
       var expectedBytes = utf8Codec.encode(expectedText);
-      client.postResponse = BASE64.encode(expectedBytes);
+      client.postResponse = base64.encode(expectedBytes);
 
       transport.writeAll(utf8Codec.encode('my request'));
       expect(transport.hasReadData, isFalse);
@@ -94,7 +94,7 @@
 
       // prepare a response
       transport.writeAll(utf8Codec.encode('request 1'));
-      client.postResponse = BASE64.encode(expectedBytes);
+      client.postResponse = base64.encode(expectedBytes);
 
       Future responseReady = transport.flush().then((_) {
         var buffer = new Uint8List(expectedBytes.length);
@@ -105,7 +105,7 @@
       // prepare a second response
       transport.writeAll(utf8Codec.encode('request 2'));
       var response2Bytes = utf8Codec.encode('response 2');
-      client.postResponse = BASE64.encode(response2Bytes);
+      client.postResponse = base64.encode(response2Bytes);
       await transport.flush();
 
       await responseReady;
diff --git a/lib/dart/test/transport/t_socket_transport_test.dart b/lib/dart/test/transport/t_socket_transport_test.dart
index 929ab17..90bffbe 100644
--- a/lib/dart/test/transport/t_socket_transport_test.dart
+++ b/lib/dart/test/transport/t_socket_transport_test.dart
@@ -18,9 +18,11 @@
 library thrift.test.transport.t_socket_transport_test;
 
 import 'dart:async';
-import 'dart:convert' show Utf8Codec, BASE64;
+import 'dart:convert' show Utf8Codec;
 import 'dart:typed_data' show Uint8List;
 
+import 'package:dart2_constant/convert.dart' show base64;
+import 'package:dart2_constant/core.dart' as core;
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';
 import 'package:thrift/thrift.dart';
@@ -30,14 +32,13 @@
 
   final requestText = 'my test request';
   final requestBytes = new Uint8List.fromList(utf8Codec.encode(requestText));
-  final requestBase64 = BASE64.encode(requestBytes);
+  final requestBase64 = base64.encode(requestBytes);
 
   final responseText = 'response 1';
   final responseBytes = new Uint8List.fromList(utf8Codec.encode(responseText));
-  final responseBase64 = BASE64.encode(responseBytes);
+  final responseBase64 = base64.encode(responseBytes);
 
-  final framedResponseBase64 =
-      BASE64.encode(_getFramedResponse(responseBytes));
+  final framedResponseBase64 = base64.encode(_getFramedResponse(responseBytes));
 
   group('TClientSocketTransport', () {
     FakeSocket socket;
@@ -117,7 +118,7 @@
       protocolFactory.message = new TMessage('foo', TMessageType.CALL, 123);
       transport = new TAsyncClientSocketTransport(
           socket, new TMessageReader(protocolFactory),
-          responseTimeout: Duration.ZERO);
+          responseTimeout: core.Duration.zero);
       await transport.open();
       transport.writeAll(requestBytes);
     });
@@ -139,7 +140,7 @@
       var response2Text = 'response 2';
       var response2Bytes =
           new Uint8List.fromList(utf8Codec.encode(response2Text));
-      var response2Base64 = BASE64.encode(response2Bytes);
+      var response2Base64 = base64.encode(response2Bytes);
       protocolFactory.message = new TMessage('foo2', TMessageType.REPLY, 124);
       socket.receiveFakeMessage(response2Base64);
 
@@ -169,7 +170,7 @@
 
       transport = new TFramedTransport(new TAsyncClientSocketTransport(
           socket, messageReader,
-          responseTimeout: Duration.ZERO));
+          responseTimeout: core.Duration.zero));
       await transport.open();
       transport.writeAll(requestBytes);
     });
@@ -275,11 +276,10 @@
     _sendPayload = data;
   }
 
-  void receiveFakeMessage(String base64) {
+  void receiveFakeMessage(String base64text) {
     if (!isOpen) throw new StateError('The socket is not open');
 
-    var message =
-        new Uint8List.fromList(BASE64.decode(base64));
+    var message = new Uint8List.fromList(base64.decode(base64text));
     _onMessageController.add(message);
   }
 }