diff --git a/symphony/lib/toolkit/fields/field.checkbox.php b/symphony/lib/toolkit/fields/field.checkbox.php
index <HASH>..<HASH> 100755
--- a/symphony/lib/toolkit/fields/field.checkbox.php
+++ b/symphony/lib/toolkit/fields/field.checkbox.php
@@ -59,7 +59,7 @@
 			$status = self::__OK__;
 			
 			return array(
-				'value' => ($data ? 'yes' : 'no')
+				'value' => (strtolower($data) == 'no' ? 'no' : 'yes')
 			);
 			
 		}
Allow for a negative value ('no') to be sent in the POST array to un-tick a checkbox.