diff --git a/data/source/database/adapter/MySql.php b/data/source/database/adapter/MySql.php
index bc49789a33..7125e6b609 100644
--- a/data/source/database/adapter/MySql.php
+++ b/data/source/database/adapter/MySql.php
@@ -446,7 +446,7 @@ protected function _column($real) {
 		switch (true) {
 			case in_array($column['type'], ['date', 'time', 'datetime', 'timestamp']):
 				return $column;
-			case ($column['type'] === 'tinyint' && $column['length'] == '1'):
+			case ($column['type'] === 'tinyint' && isset($column['length']) && $column['length'] == '1'):
 			case ($column['type'] === 'boolean'):
 				return ['type' => 'boolean'];
 			break;
@@ -508,4 +508,4 @@ protected function _buildColumn($field) {
 	}
 }
 
-?>
\ No newline at end of file
+?>