diff --git a/code/forms/GridFieldSortableRows.php b/code/forms/GridFieldSortableRows.php
index e0e6866..b2b7272 100644
--- a/code/forms/GridFieldSortableRows.php
+++ b/code/forms/GridFieldSortableRows.php
@@ -189,7 +189,7 @@ class GridFieldSortableRows implements GridField_HTMLProvider, GridField_ActionP
 		if (!$many_many) {
 			$sng=singleton($gridField->getModelClass());
 			$fieldType=$sng->db($this->sortColumn);
-			if(!$fieldType || !(strtolower($fieldType) == 'dbint' || is_subclass_of($fieldType, 'DBInt'))) {
+			if(!$fieldType || !(strtolower($fieldType) == 'int' || is_subclass_of($fieldType, 'Int') || strtolower($fieldType) == 'dbint' || is_subclass_of($fieldType, 'DBInt'))) {
 				if(is_array($fieldType)) {
 					user_error('Sort column '.$this->sortColumn.' could not be found in '.$gridField->getModelClass().'\'s ancestry', E_USER_ERROR);
 				}else {
@@ -212,8 +212,8 @@ class GridFieldSortableRows implements GridField_HTMLProvider, GridField_ActionP
 				list($parentClass, $componentClass, $parentField, $componentField, $table) = $owner->many_many((!empty($this->custom_relation_name) ? $this->custom_relation_name:$gridField->getName()));
 				$extraFields=$owner->many_many_extraFields((!empty($this->custom_relation_name) ? $this->custom_relation_name:$gridField->getName()));
 				
-				if(!$extraFields || !array_key_exists($this->sortColumn, $extraFields) || !(strtolower($extraFields[$this->sortColumn])=='dbint' || is_subclass_of('DBInt', $extraFields[$this->sortColumn]))) {
-					user_error('Sort column '.$this->sortColumn.' must be an Int, column is of type '.$extraFields[$this->sortColumn], E_USER_ERROR);
+				if(!$extraFields || !array_key_exists($this->sortColumn, $extraFields) || !(strtolower($extraFields[$this->sortColumn])=='int' || is_subclass_of('Int', $extraFields[$this->sortColumn])) || strtolower($extraFields[$this->sortColumn])=='dbint' || is_subclass_of('DBInt', $extraFields[$this->sortColumn]))) {
+					user_error('Sort column '.$this->sortColumn.' must be an instance of DBInt, column is of type '.$extraFields[$this->sortColumn], E_USER_ERROR);
 					exit;
 				}
 			}else {