diff --git a/libraries/ParserCSV.inc b/libraries/ParserCSV.inc
index 1c13dfe97337d5cde43e2e7719547f8087ced61b..e8cec48747f698a5a0f052b2dbb2764c2cf717de 100644
--- a/libraries/ParserCSV.inc
+++ b/libraries/ParserCSV.inc
@@ -214,7 +214,7 @@ class ParserCSV {
       $currentField = '';
       $fields = array();
 
-      while ($currentIndex <= strlen($line)) {
+      while ($currentIndex <= drupal_strlen($line)) {
         if ($quoted) {
           $nextQuoteIndex = strpos($line, '"', $currentIndex);