diff --git a/src/Constraint/Page.php b/src/Constraint/Page.php
index 7314456..7af66a4 100644
--- a/src/Constraint/Page.php
+++ b/src/Constraint/Page.php
@@ -25,7 +25,7 @@ public function __construct($string, $uri = '')
     protected function matches($other) : bool
     {
         $other = $this->normalizeText($other);
-        return mb_stripos($other, $this->string, null, 'UTF-8') !== false;
+        return mb_stripos($other, $this->string, 0, 'UTF-8') !== false;
     }
 
     /**