diff --git a/library/think/model/relation/BelongsTo.php b/library/think/model/relation/BelongsTo.php
index cdfa5da6..4c8b7926 100644
--- a/library/think/model/relation/BelongsTo.php
+++ b/library/think/model/relation/BelongsTo.php
@@ -184,7 +184,7 @@ class BelongsTo extends OneToOne
         $this->parent->setAttr($foreignKey, $model->$pk);
         $this->parent->save();
 
-        return $this->parent->setAttr($this->relation, $model);
+        return $this->parent->data($this->relation, $model);
     }
 
     /**
@@ -199,6 +199,6 @@ class BelongsTo extends OneToOne
         $this->parent->setAttr($foreignKey, null);
         $this->parent->save();
 
-        return $this->parent->setAttr($this->relation, null);
+        return $this->parent->data($this->relation, null);
     }
 }
diff --git a/library/think/model/relation/MorphTo.php b/library/think/model/relation/MorphTo.php
index 9c97500c..9c020b85 100644
--- a/library/think/model/relation/MorphTo.php
+++ b/library/think/model/relation/MorphTo.php
@@ -241,7 +241,7 @@ class MorphTo extends Relation
         $this->parent->setAttr($morphType, get_class($model));
         $this->parent->save();
 
-        return $this->parent->setAttr($this->relation, $model);
+        return $this->parent->data($this->relation, $model);
     }
 
     /**
@@ -258,7 +258,7 @@ class MorphTo extends Relation
         $this->parent->setAttr($morphType, null);
         $this->parent->save();
 
-        return $this->parent->setAttr($this->relation, null);
+        return $this->parent->data($this->relation, null);
     }
 
     /**