diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 819cf68..3f3e2ea 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -15,6 +15,7 @@ Yii Framework 2 Change Log
 - Bug #1582: Error messages shown via client-side validation should not be double encoded (qiangxue)
 - Bug #1591: StringValidator is accessing undefined property (qiangxue)
 - Bug #1597: Added `enableAutoLogin` to basic and advanced application templates so "remember me" now works properly (samdark)
+- Bug #1631: Charset is now explicitly set to UTF-8 when serving JSON (samdark)
 - Bug: Fixed `Call to a member function registerAssetFiles() on a non-object` in case of wrong `sourcePath` for an asset bundle (samdark)
 - Bug: Fixed incorrect event name for `yii\jui\Spinner` (samdark)
 - Bug: Json::encode() did not handle objects that implement JsonSerializable interface correctly (cebe)
diff --git a/framework/yii/web/Response.php b/framework/yii/web/Response.php
index 43e8f73..79d94dd 100644
--- a/framework/yii/web/Response.php
+++ b/framework/yii/web/Response.php
@@ -799,7 +799,7 @@ class Response extends \yii\base\Response
 					$this->content = $this->data;
 					break;
 				case self::FORMAT_JSON:
-					$this->getHeaders()->set('Content-Type', 'application/json');
+					$this->getHeaders()->set('Content-Type', 'application/json; charset=UTF-8');
 					$this->content = Json::encode($this->data);
 					break;
 				case self::FORMAT_JSONP: