diff --git a/models/VariantToShop.php b/models/VariantToShop.php
index 2939a0c..78ea540 100644
--- a/models/VariantToShop.php
+++ b/models/VariantToShop.php
@@ -90,4 +90,18 @@
             return $this->hasOne(Variant::className(), [ 'id' => 'variant_id' ]);
         }
         
+        public function afterSave($insert, $changedAttributes)
+        {
+            parent::afterSave($insert, $changedAttributes); // TODO: Change the autogenerated stub
+            
+            $variant = $this->variant;
+            if ($variant->stock - $changedAttributes['count'] >= 0){
+                $variant->stock = $variant->stock - $changedAttributes['count'] + $this->count;
+            }else{
+                $variant->stock = $this->count;
+            }
+            $variant->save();
+            
+        }
+    
     }
--
libgit2 0.21.4