diff --git a/sample_project/demo/__init__.py b/sample_project/demo/__init__.py
index 8898865..e69de29 100644
--- a/sample_project/demo/__init__.py
+++ b/sample_project/demo/__init__.py
@@ -1 +0,0 @@
-default_app_config = "demo.apps.DemoConfig"
diff --git a/sample_project/demo/admin.py b/sample_project/demo/admin.py
index 6d24173..f067d39 100644
--- a/sample_project/demo/admin.py
+++ b/sample_project/demo/admin.py
@@ -3,6 +3,7 @@ from django.contrib import admin
 from .models import Category, Post, Tag
 
 
+@admin.register(Post)
 class PostAdmin(admin.ModelAdmin):
     list_display = ("title", "author", "category", "created_at", "updated_at")
     list_filter = ("author", "category", "tags", "created_at")
@@ -22,16 +23,15 @@ class PostAdmin(admin.ModelAdmin):
     readonly_fields = ("created_at", "updated_at")
 
 
+@admin.register(Category)
 class CategoryAdmin(admin.ModelAdmin):
     list_display = ("name",)
     search_fields = ("name",)
 
 
+@admin.register(Tag)
 class TagAdmin(admin.ModelAdmin):
     list_display = ("name",)
     search_fields = ("name",)
 
 
-admin.site.register(Post, PostAdmin)
-admin.site.register(Category, CategoryAdmin)
-admin.site.register(Tag, TagAdmin)