diff --git a/composer.json b/composer.json
index f263f2f..86d1ef9 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
 	"require": {
 		"php":            ">=7.1.0",
 		"ext-json": "*",
-		"league/fractal": "^0.19.2",
+		"league/fractal": "^0.20.0",
 		"yiisoft/yii2":   "~2.0.15"
 		
 	},
diff --git a/src/JsonApiError.php b/src/JsonApiError.php
index b8e8d75..b3022bc 100644
--- a/src/JsonApiError.php
+++ b/src/JsonApiError.php
@@ -21,6 +21,7 @@ class JsonApiError extends BaseObject implements JsonSerializable
     public $source;
     public $meta = [];
 
+    #[\ReturnTypeWillChange]
     public function jsonSerialize()
     {
         $base = [