diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 4eeb74a..bcf7a8d 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -806,10 +806,13 @@
 					case 'ENUM':
 					case 'SET':
 						$attributes['CONSTRAINT'] = $this->db->escape($attributes['CONSTRAINT']);
+						$field['length'] = is_array($attributes['CONSTRAINT'])
+							? "('".implode("','", $attributes['CONSTRAINT'])."')"
+							: '('.$attributes['CONSTRAINT'].')';
 					default:
 						$field['length'] = is_array($attributes['CONSTRAINT'])
-								? "('".implode("','", $attributes['CONSTRAINT'])."')"
-								: '('.$attributes['CONSTRAINT'].')';
+							? '('.implode(',', $attributes['CONSTRAINT']).')'
+							: '('.$attributes['CONSTRAINT'].')';
 						break;
 				}
 			}