diff --git a/lib/src/sha512.dart b/lib/src/sha512.dart
index a963584..16b5724 100644
--- a/lib/src/sha512.dart
+++ b/lib/src/sha512.dart
@@ -32,7 +32,7 @@
 /// new instance.
 class Sha384 extends Hash {
   @override
-  final int blockSize = 16 * bytesPerWord;
+  final int blockSize = 32 * bytesPerWord;
 
   Sha384._();
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 7dfa266..f8dc330 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: crypto
-version: 2.1.1+1
+version: 2.1.1+2
 author: Dart Team <misc@dartlang.org>
 description: Library of cryptographic functions.
 homepage: https://www.github.com/dart-lang/crypto
diff --git a/test/hmac_sha2_test.dart b/test/hmac_sha2_test.dart
new file mode 100644
index 0000000..f442881
--- /dev/null
+++ b/test/hmac_sha2_test.dart
@@ -0,0 +1,128 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Library tag to allow the test to run on Dartium.
+import 'package:crypto/crypto.dart';
+import 'package:test/test.dart';
+
+import 'utils.dart';
+
+void main() {
+  group('rfc4231 vectors', () {
+    testCase(
+      name: 'Test Case 1',
+      key: '0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b',
+      data: '4869205468657265',
+      hmacSha224: '896fb1128abbdf196832107cd49df33f47b4b1169912ba4f53684b22',
+      hmacSha256:
+          'b0344c61d8db38535ca8afceaf0bf12b881dc200c9833da726e9376c2e32cff7',
+      hmacSha384:
+          'afd03944d84895626b0825f4ab46907f15f9dadbe4101ec682aa034c7cebc59cfaea9ea9076ede7f4af152e8b2fa9cb6',
+      hmacSha512:
+          '87aa7cdea5ef619d4ff0b4241a1d6cb02379f4e2ce4ec2787ad0b30545e17cdedaa833b7d6b8a702038b274eaea3f4e4be9d914eeb61f1702e696c203a126854',
+    );
+    testCase(
+      name: 'Test Case 2',
+      key: '4a656665',
+      data: '7768617420646f2079612077616e7420666f72206e6f7468696e673f',
+      hmacSha224: 'a30e01098bc6dbbf45690f3a7e9e6d0f8bbea2a39e6148008fd05e44',
+      hmacSha256:
+          '5bdcc146bf60754e6a042426089575c75a003f089d2739839dec58b964ec3843',
+      hmacSha384:
+          'af45d2e376484031617f78d2b58a6b1b9c7ef464f5a01b47e42ec3736322445e8e2240ca5e69e2c78b3239ecfab21649',
+      hmacSha512:
+          '164b7a7bfcf819e2e395fbe73b56e0a387bd64222e831fd610270cd7ea2505549758bf75c05a994a6d034f65f8f0e6fdcaeab1a34d4a6b4b636e070a38bce737',
+    );
+    testCase(
+      name: 'Test Case 3',
+      key: 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
+      data:
+          'dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd',
+      hmacSha224: '7fb3cb3588c6c1f6ffa9694d7d6ad2649365b0c1f65d69d1ec8333ea',
+      hmacSha256:
+          '773ea91e36800e46854db8ebd09181a72959098b3ef8c122d9635514ced565fe',
+      hmacSha384:
+          '88062608d3e6ad8a0aa2ace014c8a86f0aa635d947ac9febe83ef4e55966144b2a5ab39dc13814b94e3ab6e101a34f27',
+      hmacSha512:
+          'fa73b0089d56a284efb0f0756c890be9b1b5dbdd8ee81a3655f83e33b2279d39bf3e848279a722c806b485a47e67c807b946a337bee8942674278859e13292fb',
+    );
+    testCase(
+      name: 'Test Case 4',
+      key: '0102030405060708090a0b0c0d0e0f10111213141516171819',
+      data:
+          'cdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd',
+      hmacSha224: '6c11506874013cac6a2abc1bb382627cec6a90d86efc012de7afec5a',
+      hmacSha256:
+          '82558a389a443c0ea4cc819899f2083a85f0faa3e578f8077a2e3ff46729665b',
+      hmacSha384:
+          '3e8a69b7783c25851933ab6290af6ca77a9981480850009cc5577c6e1f573b4e6801dd23c4a7d679ccf8a386c674cffb',
+      hmacSha512:
+          'b0ba465637458c6990e5a8c5f61d4af7e576d97ff94b872de76f8050361ee3dba91ca5c11aa25eb4d679275cc5788063a5f19741120c4f2de2adebeb10a298dd',
+    );
+    testCase(
+      name: 'Test Case 5',
+      key: '0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c0c',
+      data: '546573742057697468205472756e636174696f6e',
+      hmacSha224: '0e2aea68a90c8d37c988bcdb9fca6fa8',
+      hmacSha256: 'a3b6167473100ee06e0c796c2955552b',
+      hmacSha384: '3abf34c3503b2a23a46efc619baef897',
+      hmacSha512: '415fad6271580a531d4179bc891d87a6',
+      truncation: true,
+    );
+
+    testCase(
+      name: 'Test Case 6',
+      key:
+          'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
+      data:
+          '54657374205573696e67204c6172676572205468616e20426c6f636b2d53697a65204b6579202d2048617368204b6579204669727374',
+      hmacSha224: '95e9a0db962095adaebe9b2d6f0dbce2d499f112f2d2b7273fa6870e',
+      hmacSha256:
+          '60e431591ee0b67f0d8a26aacbf5b77f8e0bc6213728c5140546040f0ee37f54',
+      hmacSha384:
+          '4ece084485813e9088d2c63a041bc5b44f9ef1012a2b588f3cd11f05033ac4c60c2ef6ab4030fe8296248df163f44952',
+      hmacSha512:
+          '80b24263c7c1a3ebb71493c1dd7be8b49b46d1f41b4aeec1121b013783f8f3526b56d037e05f2598bd0fd2215d6a1e5295e64f73f63f0aec8b915a985d786598',
+    );
+    testCase(
+      name: 'Test Case 7',
+      key:
+          'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
+      data:
+          '5468697320697320612074657374207573696e672061206c6172676572207468616e20626c6f636b2d73697a65206b657920616e642061206c6172676572207468616e20626c6f636b2d73697a6520646174612e20546865206b6579206e6565647320746f20626520686173686564206265666f7265206265696e6720757365642062792074686520484d414320616c676f726974686d2e',
+      hmacSha224: '3a854166ac5d9f023f54d517d0b39dbd946770db9c2b95c9f6f565d1',
+      hmacSha256:
+          '9b09ffa71b942fcb27635fbcd5b0e944bfdc63644f0713938a7f51535c3a35e2',
+      hmacSha384:
+          '6617178e941f020d351e2f254e8fd32c602420feb0b8fb9adccebb82461e99c5a678cc31e799176d3860e6110c46523e',
+      hmacSha512:
+          'e37b6a775dc87dbaa4dfa9f96e5e3ffddebd71f8867289865df5a32d20cdc944b6022cac3c4982b10d5eeb55c3e4de15134676fb6de0446065c97440fa8c6a58',
+    );
+  });
+}
+
+testCase({
+  String name,
+  String key,
+  String data,
+  String hmacSha224,
+  String hmacSha256,
+  String hmacSha384,
+  String hmacSha512,
+  bool truncation = false,
+}) {
+  test(name, () {
+    final _key = bytesFromHexString(key);
+    final _data = bytesFromHexString(data);
+
+    expect(Hmac(sha224, _key).convert(_data).toString(),
+        truncation ? startsWith(hmacSha224) : hmacSha224);
+    expect(Hmac(sha256, _key).convert(_data).toString(),
+        truncation ? startsWith(hmacSha256) : hmacSha256);
+    expect(Hmac(sha384, _key).convert(_data).toString(),
+        truncation ? startsWith(hmacSha384) : hmacSha384);
+    expect(Hmac(sha512, _key).convert(_data).toString(),
+        truncation ? startsWith(hmacSha512) : hmacSha512);
+  });
+}
diff --git a/test/sha_monte_test.dart b/test/sha_monte_test.dart
index 5a947d1..baff420 100644
--- a/test/sha_monte_test.dart
+++ b/test/sha_monte_test.dart
@@ -3,6 +3,8 @@
 import 'package:test/test.dart';
 import 'package:crypto/crypto.dart';
 
+import 'utils.dart';
+
 main() {
   group("Monte Vectors", () {
     monteTest(
@@ -79,12 +81,3 @@
     expect(run().toList(), expected);
   });
 }
-
-final toupleMatch = RegExp('([0-9a-fA-F]{2})');
-Uint8List bytesFromHexString(String message) {
-  var seed = <int>[];
-  for (var match in toupleMatch.allMatches(message)) {
-    seed.add(int.parse(match.group(0), radix: 16));
-  }
-  return Uint8List.fromList(seed);
-}
diff --git a/test/utils.dart b/test/utils.dart
index 09360f5..8ac1215 100644
--- a/test/utils.dart
+++ b/test/utils.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:typed_data';
+
 import 'package:crypto/crypto.dart';
 import 'package:test/test.dart';
 
@@ -10,3 +12,13 @@
   var hmac = Hmac(hash, key);
   expect(hmac.convert(input).toString(), startsWith(mac));
 }
+
+final toupleMatch = RegExp('([0-9a-fA-F]{2})');
+
+Uint8List bytesFromHexString(String message) {
+  var bytes = <int>[];
+  for (var match in toupleMatch.allMatches(message)) {
+    bytes.add(int.parse(match.group(0), radix: 16));
+  }
+  return Uint8List.fromList(bytes);
+}