diff --git a/Model/Behavior/OriginalKeyBehavior.php b/Model/Behavior/OriginalKeyBehavior.php
index f393fcc5..e8f5d0b1 100644
--- a/Model/Behavior/OriginalKeyBehavior.php
+++ b/Model/Behavior/OriginalKeyBehavior.php
@@ -59,7 +59,9 @@ public function beforeSave(Model $model, $options = array()) {
 			return true;
 		}
 		if (! isset($model->data[$model->alias]['key']) || $model->data[$model->alias]['key'] === '') {
-			$model->data[$model->alias]['key'] = self::generateKey($model->alias, $model->useDbConfig);
+			$plugin = Inflector::underscore($model->alias);
+			$keyNumber = $model->find('count', ['recursive' => -1]) + 1;
+			$model->data[$model->alias]['key'] = $plugin . '_key_' . $keyNumber;
 		}
 		return true;
 	}
@@ -74,7 +76,7 @@ public function beforeSave(Model $model, $options = array()) {
 	public static function generateKey($plugin, $dataSource) {
 		if ($dataSource !== 'test' || self::$isUnitRandomKey) {
 			return Security::hash($plugin . mt_rand() . microtime(), 'md5');
-		} else {
+			} else {
 			return Security::hash($plugin, 'md5');
 		}
 	}
diff --git a/TestSuite/NetCommonsTreeBehaviorCase.php b/TestSuite/NetCommonsTreeBehaviorCase.php
index 0354e5b4..92e7c1ec 100644
--- a/TestSuite/NetCommonsTreeBehaviorCase.php
+++ b/TestSuite/NetCommonsTreeBehaviorCase.php
@@ -85,6 +85,7 @@ public function startTest($method) {
 		if (version_compare(PHP_VERSION, '7.0.0') < 0) {
 			$this->markTestSkipped('php 7.x以上でテストができます。');
 		}
+		parent::__construct($name, $data, $dataName);
 	}
 
 /**