diff --git a/src/Zend/Media/Asf/Object/StreamProperties.php b/src/Zend/Media/Asf/Object/StreamProperties.php
index b341efa..c69e62a 100644
--- a/src/Zend/Media/Asf/Object/StreamProperties.php
+++ b/src/Zend/Media/Asf/Object/StreamProperties.php
@@ -163,12 +163,12 @@ final class Zend_Media_Asf_Object_StreamProperties extends Zend_Media_Asf_Object
                 // break intentionally omitted
             case self::BINARY_MEDIA:
                 $this->_typeSpecificData = array
-                    ('majorMediaType' => $this->_reader->getGUID(),
-                     'mediaSubtype' => $this->_reader->getGUID(),
+                    ('majorMediaType' => $this->_reader->readGUID(),
+                     'mediaSubtype' => $this->_reader->readGUID(),
                      'fixedSizeSamples' => $this->_reader->readUInt32LE(),
                      'temporalCompression' => $this->_reader->readUInt32LE(),
                      'sampleSize' => $this->_reader->readUInt32LE(),
-                     'formatType' => $this->_reader->getGUID());
+                     'formatType' => $this->_reader->readGUID());
                 $formatDataSize = $this->_reader->readUInt32LE();
                 $this->_typeSpecificData['formatData'] =
                     $this->_reader->read($formatDataSize);