diff --git a/lib/Doctrine/ORM/Query/Expr/Composite.php b/lib/Doctrine/ORM/Query/Expr/Composite.php
index 0d606a9b0..036b241a5 100644
--- a/lib/Doctrine/ORM/Query/Expr/Composite.php
+++ b/lib/Doctrine/ORM/Query/Expr/Composite.php
@@ -39,30 +39,30 @@ class Composite extends Base
         if ($this->count() === 1) {
             return (string) $this->_parts[0];
         }
-        
+
         $components = array();
-        
+
         foreach ($this->_parts as $part) {
             $components[] = $this->processQueryPart($part);
         }
-        
+
         return implode($this->_separator, $components);
     }
-    
-    
+
+
     private function processQueryPart($part)
     {
         $queryPart = (string) $part;
-        
+
         if (is_object($part) && $part instanceof self && $part->count() > 1) {
             return $this->_preSeparator . $queryPart . $this->_postSeparator;
         }
-        
+
         // Fixes DDC-1237: User may have added a where item containing nested expression (with "OR" or "AND")
-        if (mb_stripos($queryPart, ' OR ') !== false || mb_stripos($queryPart, ' AND ') !== false) {
+        if (stripos($queryPart, ' OR ') !== false || stripos($queryPart, ' AND ') !== false) {
             return $this->_preSeparator . $queryPart . $this->_postSeparator;
         }
-        
+
         return $queryPart;
     }
 }
\ No newline at end of file