diff --git a/library/think/model/relation/BelongsTo.php b/library/think/model/relation/BelongsTo.php
index 630719c0..9a308d23 100644
--- a/library/think/model/relation/BelongsTo.php
+++ b/library/think/model/relation/BelongsTo.php
@@ -197,7 +197,7 @@ class BelongsTo extends OneToOne
         $this->parent->setAttr($foreignKey, $model->$pk);
         $this->parent->save();
 
-        return $this->parent->data($this->relation, $model);
+        return $this->parent->setAttr($this->relation, $model);
     }
 
     /**
@@ -212,6 +212,6 @@ class BelongsTo extends OneToOne
         $this->parent->setAttr($foreignKey, null);
         $this->parent->save();
 
-        return $this->parent->data($this->relation, null);
+        return $this->parent->setAttr($this->relation, null);
     }
 }
diff --git a/library/think/model/relation/MorphTo.php b/library/think/model/relation/MorphTo.php
index d67989c4..7dc22652 100644
--- a/library/think/model/relation/MorphTo.php
+++ b/library/think/model/relation/MorphTo.php
@@ -251,7 +251,7 @@ class MorphTo extends Relation
         $this->parent->setAttr($morphType, get_class($model));
         $this->parent->save();
 
-        return $this->parent->data($this->relation, $model);
+        return $this->parent->setAttr($this->relation, $model);
     }
 
     /**
@@ -268,7 +268,7 @@ class MorphTo extends Relation
         $this->parent->setAttr($morphType, null);
         $this->parent->save();
 
-        return $this->parent->data($this->relation, null);
+        return $this->parent->setAttr($this->relation, null);
     }
 
     /**