diff --git a/src/Symfony/Component/Serializer/Encoder/JsonEncoder.php b/src/Symfony/Component/Serializer/Encoder/JsonEncoder.php
index cf4a89ca1ab5f..27f749b637bf0 100644
--- a/src/Symfony/Component/Serializer/Encoder/JsonEncoder.php
+++ b/src/Symfony/Component/Serializer/Encoder/JsonEncoder.php
@@ -23,10 +23,10 @@ class JsonEncoder implements EncoderInterface, DecoderInterface
     protected $encodingImpl;
     protected $decodingImpl;
 
-    public function __construct(JsonEncode $encodingImpl = null, JsonDecode $decodingImpl = null)
+    public function __construct(JsonEncode $encodingImpl = null, JsonDecode $decodingImpl = null, array $defaultContext = [])
     {
-        $this->encodingImpl = $encodingImpl ?? new JsonEncode();
-        $this->decodingImpl = $decodingImpl ?? new JsonDecode([JsonDecode::ASSOCIATIVE => true]);
+        $this->encodingImpl = $encodingImpl ?? new JsonEncode($defaultContext);
+        $this->decodingImpl = $decodingImpl ?? new JsonDecode(array_merge([JsonDecode::ASSOCIATIVE => true], $defaultContext));
     }
 
     /**
diff --git a/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncoderTest.php b/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncoderTest.php
index c1d7d496cce71..6cd1f82b1ab6c 100644
--- a/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncoderTest.php
+++ b/src/Symfony/Component/Serializer/Tests/Encoder/JsonEncoderTest.php
@@ -66,6 +66,22 @@ public function testOptions()
         $this->assertEquals($expected, $this->serializer->serialize($arr, 'json'), 'Context should not be persistent');
     }
 
+    public function testWithDefaultContext()
+    {
+        $defaultContext = [
+            'json_encode_options' => \JSON_UNESCAPED_UNICODE,
+            'json_decode_associative' => false,
+        ];
+
+        $encoder = new JsonEncoder(null, null, $defaultContext);
+
+        $data = new \stdClass();
+        $data->msg = '你好';
+
+        $this->assertEquals('{"msg":"你好"}', $json = $encoder->encode($data, 'json'));
+        $this->assertEquals($data, $encoder->decode($json, 'json'));
+    }
+
     public function testEncodeNotUtf8WithoutPartialOnError()
     {
         $this->expectException(UnexpectedValueException::class);