diff --git a/inc/inc.ClassSettings.php b/inc/inc.ClassSettings.php
index 95c4b1cbf..b937034f0 100644
--- a/inc/inc.ClassSettings.php
+++ b/inc/inc.ClassSettings.php
@@ -434,7 +434,7 @@ class Settings { /* {{{ */
 		$this->_rootDir = strval($tab["rootDir"]);
 		$this->_httpRoot = strval($tab["httpRoot"]);
 		$this->_contentDir = strval($tab["contentDir"]);
-		if(substr($this->_contentDir, -1, 1) != DIRECTORY_SEPARATOR)
+		if($this->_contentDir && substr($this->_contentDir, -1, 1) != DIRECTORY_SEPARATOR)
 			$this->_contentDir .= DIRECTORY_SEPARATOR;
 		$this->_cacheDir = strval($tab["cacheDir"]);
 		$this->_stagingDir = strval($tab["stagingDir"]);