diff --git a/composer.json b/composer.json
index 4b10d3d..b940033 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
     "ext-curl": "*",
     "skrz/meta": "^3.1",
     "symfony/finder": "~2.7|~3.0|~4.0",
-    "symfony/yaml": "~2.7|~3.0|~4.0"
+    "symfony/yaml": "~4.0"
   },
   "require-dev": {
     "cdn77/coding-standard": "^0.5",
diff --git a/src/Response/ResponseData.php b/src/Response/ResponseData.php
index d0a0632..ac0321f 100644
--- a/src/Response/ResponseData.php
+++ b/src/Response/ResponseData.php
@@ -97,6 +97,9 @@ public function getYaml() : ?string
      */
     public function getParsedYaml(int $flags = 0) : array
     {
-        return Yaml::parse($this->getYaml(), $flags);
+        return Yaml::parse(
+            (string) $this->getYaml(),
+            $flags
+        );
     }
 }