diff --git a/src/StreamInterface.php b/src/StreamInterface.php
index f68f391..aac7124 100644
--- a/src/StreamInterface.php
+++ b/src/StreamInterface.php
@@ -21,6 +21,7 @@ interface StreamInterface
      *
      * This method MUST NOT raise an exception in order to conform with PHP's
      * string casting operations.
+     * @throws void
      *
      * @see http://php.net/manual/en/language.oop5.magic.php#object.tostring
      * @return string