diff --git a/Slim/Http/Response.php b/Slim/Http/Response.php
index 9b5272e64..33a9eda4c 100644
--- a/Slim/Http/Response.php
+++ b/Slim/Http/Response.php
@@ -359,7 +359,7 @@ public function withJson($data, $status = null, $encodingOptions = 0)
             throw new \RuntimeException(json_last_error_msg(), json_last_error());
         }
 
-        $responseWithJson = $response->withHeader('Content-Type', 'application/json;charset=utf-8');
+        $responseWithJson = $response->withHeader('Content-Type', 'application/json');
         if (isset($status)) {
             return $responseWithJson->withStatus($status);
         }
diff --git a/tests/Http/ResponseTest.php b/tests/Http/ResponseTest.php
index b09fcfc0a..dac4316df 100755
--- a/tests/Http/ResponseTest.php
+++ b/tests/Http/ResponseTest.php
@@ -292,7 +292,7 @@ public function testWithJson()
 
         $this->assertNotEquals($response->getStatusCode(), $originalResponse->getStatusCode());
         $this->assertEquals(201, $response->getStatusCode());
-        $this->assertEquals('application/json;charset=utf-8', $response->getHeaderLine('Content-Type'));
+        $this->assertEquals('application/json', $response->getHeaderLine('Content-Type'));
 
         $body = $response->getBody();
         $body->rewind();