diff --git a/README.md b/README.md
index c5462ef..dd61480 100644
--- a/README.md
+++ b/README.md
@@ -281,5 +281,5 @@ In that case, a call to the `load()` method will also automatically trigger a ca
 The `relationKeyName` property can be used to decide how the relations data will be retrieved from the data parameter. 
 
 Possible constants values are:
-* `SaveRelationsBehavior::RELATION_KEY_FORMNAME` (default): the key name will be compute using the model [`formName()`](https://www.yiiframework.com/doc/api/2.0/yii-base-model#formName()-detail) method
-* `SaveRelationsBehavior::RELATION_KEY_MODELNAME`: the relation name as defined in the behavior declarations will be used
+* `SaveRelationsBehavior::RELATION_KEY_FORM_NAME` (default): the key name will be compute using the model [`formName()`](https://www.yiiframework.com/doc/api/2.0/yii-base-model#formName()-detail) method
+* `SaveRelationsBehavior::RELATION_KEY_RELATION_NAME`: the relation name as defined in the behavior declarations will be used
diff --git a/src/SaveRelationsBehavior.php b/src/SaveRelationsBehavior.php
index 75ed45b..19374db 100644
--- a/src/SaveRelationsBehavior.php
+++ b/src/SaveRelationsBehavior.php
@@ -27,11 +27,11 @@ use yii\helpers\VarDumper;
 class SaveRelationsBehavior extends Behavior
 {
 
-    const RELATION_KEY_FORMNAME = 'formName';
-    const RELATION_KEY_MODELNAME = 'modelName';
+    const RELATION_KEY_FORM_NAME = 'formName';
+    const RELATION_KEY_RELATION_NAME = 'relationName';
 
     public $relations = [];
-    public $relationKeyName = self::RELATION_KEY_FORMNAME;
+    public $relationKeyName = self::RELATION_KEY_FORM_NAME;
 
     private $_relations = [];
     private $_oldRelationValue = []; // Store initial relations value
@@ -776,10 +776,10 @@ class SaveRelationsBehavior extends Behavior
     private function _getRelationKeyName($relationName)
     {
         switch ($this->relationKeyName) {
-            case self::RELATION_KEY_MODELNAME:
+            case self::RELATION_KEY_RELATION_NAME:
                 $keyName = $relationName;
                 break;
-            case self::RELATION_KEY_FORMNAME:
+            case self::RELATION_KEY_FORM_NAME:
                 /** @var BaseActiveRecord $owner */
                 $owner = $this->owner;
                 /** @var ActiveQuery $relation */
diff --git a/tests/SaveRelationsBehaviorTest.php b/tests/SaveRelationsBehaviorTest.php
index 099e5f7..d62450e 100644
--- a/tests/SaveRelationsBehaviorTest.php
+++ b/tests/SaveRelationsBehaviorTest.php
@@ -852,7 +852,7 @@ class SaveRelationsBehaviorTest extends \PHPUnit_Framework_TestCase
         $company->attachBehavior('saveRelations', [
             'class'           => SaveRelationsBehavior::className(),
             'relations'       => ['users'],
-            'relationKeyName' => SaveRelationsBehavior::RELATION_KEY_MODELNAME
+            'relationKeyName' => SaveRelationsBehavior::RELATION_KEY_RELATION_NAME
         ]);
 
         $data = [