diff --git a/src/Network/CurlResult.php b/src/Network/CurlResult.php
index 2f5c94187..26fe7a478 100644
--- a/src/Network/CurlResult.php
+++ b/src/Network/CurlResult.php
@@ -134,6 +134,7 @@ class CurlResult
 
 		$this->body = substr($result, strlen($header));
 		$this->header = $header;
+		$this->header_fields = []; // Is filled on demand
 	}
 
 	private function checkSuccess()