diff --git a/samples/Sample_27_Field.php b/samples/Sample_27_Field.php
index b5be12ca..ec9dbe25 100644
--- a/samples/Sample_27_Field.php
+++ b/samples/Sample_27_Field.php
@@ -28,7 +28,7 @@ $textrun->addText('here:');
 
 $indexEntryText = new TextRun();
 $indexEntryText->addText('My ');
-$indexEntryText->addText('bold index', ['bold' => true]);
+$indexEntryText->addText('bold index', array('bold' => true));
 $indexEntryText->addText(' entry');
 
 $textrun = $section->addTextRun();