diff --git a/src/S3/MultipartUploader.php b/src/S3/MultipartUploader.php
index 3387da59e1..5654e88097 100644
--- a/src/S3/MultipartUploader.php
+++ b/src/S3/MultipartUploader.php
@@ -214,9 +214,9 @@ protected function getCompleteParams()
     private function decorateWithHashes(Stream $stream, array &$data)
     {
         // Decorate source with a hashing stream
-        $hash = new PhpHash('sha256', ['base64' => true]);
+        $hash = new PhpHash('sha256');
         return new HashingStream($stream, $hash, function ($result) use (&$data) {
-            $data['ContentSHA256'] = $result;
+            $data['ContentSHA256'] = bin2hex($result);
         });
     }
 }
diff --git a/tests/Integ/S3MultipartTest.php b/tests/Integ/S3MultipartTest.php
index d8876a04e6..080f2d1ddb 100644
--- a/tests/Integ/S3MultipartTest.php
+++ b/tests/Integ/S3MultipartTest.php
@@ -4,7 +4,6 @@
 use Aws\Exception\MultipartUploadException;
 use Aws\S3\BatchDelete;
 use Aws\S3\MultipartUploader;
-use Aws\Test\Integ\IntegUtils;
 use GuzzleHttp\Psr7\NoSeekStream;
 use GuzzleHttp\Psr7;
 
@@ -18,25 +17,26 @@ class S3Multipart extends \PHPUnit_Framework_TestCase
     public static function setUpBeforeClass()
     {
         $client = self::getSdk()->createS3();
-        if (!$client->doesBucketExist(self::BUCKET)) {
-            $client->createBucket(['Bucket' => self::BUCKET]);
-            $client->waitUntil('BucketExists', ['Bucket' => self::BUCKET]);
+        if (!$client->doesBucketExist(self::getBucketName())) {
+            $client->createBucket(['Bucket' => self::getBucketName()]);
+            $client->waitUntil('BucketExists', ['Bucket' => self::getBucketName()]);
         }
     }
 
     public static function tearDownAfterClass()
     {
         $client = self::getSdk()->createS3();
-        BatchDelete::fromListObjects($client, ['Bucket' => self::BUCKET])->delete();
-        $client->deleteBucket(['Bucket' => self::BUCKET]);
+        BatchDelete::fromListObjects($client, ['Bucket' => self::getBucketName()])->delete();
+        $client->deleteBucket(['Bucket' => self::getBucketName()]);
+        $client->waitUntil('BucketNotExists', ['Bucket' => self::getBucketName()]);
     }
 
     public function useCasesProvider()
     {
         return [
             ['SeekableSerialUpload', true, 1],
-            ['NonSeekableSerialUpload', false, 3],
-            ['SeekableConcurrentUpload', true, 1],
+            ['NonSeekableSerialUpload', false, 1],
+            ['SeekableConcurrentUpload', true, 3],
             ['NonSeekableConcurrentUpload', false, 3],
         ];
     }
@@ -62,7 +62,7 @@ public function testMultipartUpload($key, $seekable, $concurrency)
 
         // Create the uploader
         $uploader = new MultipartUploader($client, $stream, [
-            'bucket'      => self::BUCKET,
+            'bucket'      => self::getBucketName(),
             'key'         => $key,
             'concurrency' => $concurrency
         ]);
@@ -84,4 +84,16 @@ public function testMultipartUpload($key, $seekable, $concurrency)
 
         @unlink($tmpFile);
     }
+
+
+    private static function getBucketName()
+    {
+        static $bucketName;
+
+        if (empty($bucketName)) {
+            $bucketName = self::getResourcePrefix() . self::BUCKET;
+        }
+
+        return $bucketName;
+    }
 }