diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index d9ecc45..af90316 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -211,7 +211,7 @@
 				return $this;
 			}
 
-			$rules = explode('|', $rules);
+			$rules = preg_split('/\|(?![^\[]*\])/', $rules);
 		}
 
 		// If the field label wasn't passed we use the field name