diff --git a/src/Signature.php b/src/Signature.php
index 60eda06..48e6c00 100644
--- a/src/Signature.php
+++ b/src/Signature.php
@@ -42,6 +42,7 @@ public function __construct( $accessKey, $secretKey, $options, $token = null ) {
             'origin',
             'range',
             'transfer-encoding',
+            'pic-operations',
         ];
         date_default_timezone_set($this->options['timezone']);
     }