diff --git a/framework/core/src/Event/ConfigurePostTypes.php b/framework/core/src/Event/ConfigurePostTypes.php
index 577103a0f..768db2b48 100644
--- a/framework/core/src/Event/ConfigurePostTypes.php
+++ b/framework/core/src/Event/ConfigurePostTypes.php
@@ -9,6 +9,9 @@
 
 namespace Flarum\Event;
 
+/**
+ * @deprecated in beta 15, remove in beta 16. Use the Post extender instead.
+ */
 class ConfigurePostTypes
 {
     private $models;
diff --git a/framework/core/src/Extend/Post.php b/framework/core/src/Extend/Post.php
new file mode 100644
index 000000000..f750dbe2a
--- /dev/null
+++ b/framework/core/src/Extend/Post.php
@@ -0,0 +1,39 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extend;
+
+use Flarum\Extension\Extension;
+use Flarum\Post\Post as PostModel;
+use Illuminate\Contracts\Container\Container;
+
+class Post implements ExtenderInterface
+{
+    private $postTypes = [];
+
+    /**
+     * Register a new post type. This is generally done for custom 'event posts',
+     * such as those that appear when a discussion is renamed.
+     *
+     * @param string $postType: The ::class attribute of the custom Post type that is being added.
+     */
+    public function type(string $postType)
+    {
+        $this->postTypes[] = $postType;
+
+        return $this;
+    }
+
+    public function extend(Container $container, Extension $extension = null)
+    {
+        foreach ($this->postTypes as $postType) {
+            PostModel::setModel($postType::$type, $postType);
+        }
+    }
+}
diff --git a/framework/core/src/Post/Post.php b/framework/core/src/Post/Post.php
index 89bd87d43..fc9ef843b 100644
--- a/framework/core/src/Post/Post.php
+++ b/framework/core/src/Post/Post.php
@@ -218,7 +218,7 @@ class Post extends AbstractModel
      * @param string $model The class name of the model for that type.
      * @return void
      */
-    public static function setModel($type, $model)
+    public static function setModel(string $type, string $model)
     {
         static::$models[$type] = $model;
     }
diff --git a/framework/core/src/Post/PostServiceProvider.php b/framework/core/src/Post/PostServiceProvider.php
index 5fda0c859..be1c9d7c7 100644
--- a/framework/core/src/Post/PostServiceProvider.php
+++ b/framework/core/src/Post/PostServiceProvider.php
@@ -21,19 +21,20 @@ class PostServiceProvider extends AbstractServiceProvider
     {
         CommentPost::setFormatter($this->app->make('flarum.formatter'));
 
-        $this->registerPostTypes();
+        $this->setPostTypes();
 
         $events = $this->app->make('events');
         $events->subscribe(PostPolicy::class);
     }
 
-    public function registerPostTypes()
+    protected function setPostTypes()
     {
         $models = [
             CommentPost::class,
             DiscussionRenamedPost::class
         ];
 
+        // Deprecated in beta 15, remove in beta 16.
         $this->app->make('events')->dispatch(
             new ConfigurePostTypes($models)
         );
diff --git a/framework/core/tests/integration/extenders/ModelTest.php b/framework/core/tests/integration/extenders/ModelTest.php
index 1dd4fc057..608c7aadc 100644
--- a/framework/core/tests/integration/extenders/ModelTest.php
+++ b/framework/core/tests/integration/extenders/ModelTest.php
@@ -326,7 +326,7 @@ class ModelTest extends TestCase
 
         $this->app();
 
-        $post = new CustomPost;
+        $post = new ModelTestCustomPost;
 
         $this->assertEquals(42, $post->answer);
 
@@ -416,7 +416,7 @@ class ModelTest extends TestCase
     }
 }
 
-class CustomPost extends AbstractEventPost
+class ModelTestCustomPost extends AbstractEventPost
 {
     /**
      * {@inheritdoc}
diff --git a/framework/core/tests/integration/extenders/PostTest.php b/framework/core/tests/integration/extenders/PostTest.php
new file mode 100644
index 000000000..a91f12d77
--- /dev/null
+++ b/framework/core/tests/integration/extenders/PostTest.php
@@ -0,0 +1,58 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\extenders;
+
+use Flarum\Extend;
+use Flarum\Post\AbstractEventPost;
+use Flarum\Post\MergeableInterface;
+use Flarum\Post\Post;
+use Flarum\Tests\integration\TestCase;
+
+class PostTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function custom_post_type_doesnt_exist_by_default()
+    {
+        $this->assertArrayNotHasKey('customPost', Post::getModels());
+    }
+
+    /**
+     * @test
+     */
+    public function custom_post_type_exists_if_added()
+    {
+        $this->extend((new Extend\Post)->type(PostTestCustomPost::class));
+
+        // Needed for extenders to be booted
+        $this->app();
+
+        $this->assertArrayHasKey('customPost', Post::getModels());
+    }
+}
+
+class PostTestCustomPost extends AbstractEventPost implements MergeableInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static $type = 'customPost';
+
+    /**
+     * {@inheritdoc}
+     */
+    public function saveAfter(Post $previous = null)
+    {
+        $this->save();
+
+        return $this;
+    }
+}