diff --git a/filesystem/FileNameFilter.php b/filesystem/FileNameFilter.php
index <HASH>..<HASH> 100644
--- a/filesystem/FileNameFilter.php
+++ b/filesystem/FileNameFilter.php
@@ -97,7 +97,7 @@ class FileNameFilter {
 	 * @return Transliterator|NULL
 	 */
 	function getTransliterator() {
-		if(!$this->transliterator === null && self::$default_use_transliterator) {
+		if($this->transliterator === null && self::$default_use_transliterator) {
 			$this->transliterator = Object::create('Transliterator');
 		} 
 		return $this->transliterator;
BUGFIX Fixed double negation of transliterator checks in FileNameFilter, which meant it wasn't used by default when filtering SiteTree->URLSegment