diff --git a/tests/PhpWordTests/Writer/Word2007/Part/DocumentTest.php b/tests/PhpWordTests/Writer/Word2007/Part/DocumentTest.php
index 98449f3b..00582e12 100644
--- a/tests/PhpWordTests/Writer/Word2007/Part/DocumentTest.php
+++ b/tests/PhpWordTests/Writer/Word2007/Part/DocumentTest.php
@@ -408,7 +408,7 @@ class DocumentTest extends \PHPUnit\Framework\TestCase
         // behind
         $element = $doc->getElement('/w:document/w:body/w:p[2]/w:r/w:pict/v:shape');
         $style = $element->getAttribute('style');
-        self::assertRegExp('/z\-index:\-[0-9]*/', $style);
+        self::assertMatchesRegularExpression('/z\-index:\-[0-9]*/', $style);
 
         // square
         $element = $doc->getElement('/w:document/w:body/w:p[4]/w:r/w:pict/v:shape/w10:wrap');