diff --git a/framework/core/src/Database/AbstractModel.php b/framework/core/src/Database/AbstractModel.php
index 5a74e0fae..d6f7b4ce6 100644
--- a/framework/core/src/Database/AbstractModel.php
+++ b/framework/core/src/Database/AbstractModel.php
@@ -78,7 +78,11 @@ abstract class AbstractModel extends Eloquent
      */
     public function __construct(array $attributes = [])
     {
-        $this->attributes = Arr::get(static::$defaults, static::class, []);
+        $this->attributes = [];
+
+        foreach (array_merge(array_reverse(class_parents($this)), [static::class]) as $class) {
+            $this->attributes = array_merge($this->attributes, Arr::get(static::$defaults, $class, []));
+        }
 
         // Deprecated in beta 13, remove in beta 14.
         static::$dispatcher->dispatch(
@@ -103,7 +107,13 @@ abstract class AbstractModel extends Eloquent
             new ConfigureModelDates($this, $this->dates)
         );
 
-        return array_merge($this->dates, Arr::get(static::$dateAttributes, static::class, []));
+        $dates = $this->dates;
+
+        foreach (array_merge(array_reverse(class_parents($this)), [static::class]) as $class) {
+            $dates = array_merge($dates, Arr::get(static::$dateAttributes, $class, []));
+        }
+
+        return $dates;
     }
 
     /**
@@ -141,10 +151,11 @@ abstract class AbstractModel extends Eloquent
      */
     protected function getCustomRelation($name)
     {
-        $relation = Arr::get(static::$customRelations, static::class.".$name", null);
-
-        if (! is_null($relation)) {
-            return $relation($this);
+        foreach (array_merge([static::class], class_parents($this)) as $class) {
+            $relation = Arr::get(static::$customRelations, $class.".$name", null);
+            if (! is_null($relation)) {
+                return $relation($this);
+            }
         }
 
         // Deprecated, remove in beta 14
diff --git a/framework/core/tests/integration/extenders/ModelTest.php b/framework/core/tests/integration/extenders/ModelTest.php
index f06a0ad34..dc0629332 100644
--- a/framework/core/tests/integration/extenders/ModelTest.php
+++ b/framework/core/tests/integration/extenders/ModelTest.php
@@ -13,7 +13,9 @@ use Carbon\Carbon;
 use Flarum\Discussion\Discussion;
 use Flarum\Extend;
 use Flarum\Group\Group;
+use Flarum\Post\AbstractEventPost;
 use Flarum\Post\CommentPost;
+use Flarum\Post\DiscussionRenamedPost;
 use Flarum\Post\Post;
 use Flarum\Tests\integration\RetrievesAuthorizedUsers;
 use Flarum\Tests\integration\TestCase;
@@ -34,6 +36,21 @@ class ModelTest extends TestCase
         ]);
     }
 
+    protected function prepPostsHierarchy()
+    {
+        $this->prepareDatabase([
+            'users' => [
+                $this->normalUser(),
+            ],
+            'discussions' => [
+                ['id' => 1, 'title' => 'Discussion with post', 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'first_post_id' => 1, 'comment_count' => 1, 'is_private' => 0],
+            ],
+            'posts' => [
+                ['id' => 1, 'discussion_id' => 1, 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 2, 'type' => 'discussionRenamed', 'content' => '<t><p>can i haz relationz?</p></t>'],
+            ],
+        ]);
+    }
+
     /**
      * @test
      */
@@ -152,14 +169,7 @@ class ModelTest extends TestCase
                 ->belongsTo('ancestor', Discussion::class, 'discussion_id')
         );
 
-        $this->prepareDatabase([
-            'discussions' => [
-                ['id' => 1, 'title' => 'Discussion with post', 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 1, 'first_post_id' => 1, 'comment_count' => 1, 'is_private' => 0],
-            ],
-            'posts' => [
-                ['id' => 1, 'discussion_id' => 1, 'created_at' => Carbon::now()->toDateTimeString(), 'user_id' => 1, 'type' => 'comment', 'content' => '<t><p>can i haz relationz?</p></t>'],
-            ],
-        ]);
+        $this->prepPostsHierarchy();
 
         $post = CommentPost::find(1);
 
@@ -167,6 +177,45 @@ class ModelTest extends TestCase
         $this->assertEquals(1, $post->ancestor->id);
     }
 
+    /**
+     * @test
+     */
+    public function custom_relationship_prioritizes_child_classes_within_2_parent_classes()
+    {
+        $this->extend(
+            (new Extend\Model(Post::class))
+                ->belongsTo('ancestor', User::class, 'user_id'),
+            (new Extend\Model(AbstractEventPost::class))
+                ->belongsTo('ancestor', Discussion::class, 'discussion_id')
+        );
+
+        $this->prepPostsHierarchy();
+
+        $post = DiscussionRenamedPost::find(1);
+
+        $this->assertInstanceOf(Discussion::class, $post->ancestor);
+        $this->assertEquals(1, $post->ancestor->id);
+    }
+
+    /**
+     * @test
+     */
+    public function custom_relationship_prioritizes_child_classes_within_child_class_and_immediate_parent()
+    {
+        $this->extend(
+            (new Extend\Model(AbstractEventPost::class))
+                ->belongsTo('ancestor', Discussion::class, 'discussion_id'),
+            (new Extend\Model(DiscussionRenamedPost::class))
+                ->belongsTo('ancestor', User::class, 'user_id')
+        );
+
+        $this->prepPostsHierarchy();
+        $post = DiscussionRenamedPost::find(1);
+
+        $this->assertInstanceOf(User::class, $post->ancestor);
+        $this->assertEquals(2, $post->ancestor->id);
+    }
+
     /**
      * @test
      */
@@ -261,6 +310,31 @@ class ModelTest extends TestCase
         $this->assertEquals(42, $post->answer);
     }
 
+    /**
+     * @test
+     */
+    public function custom_default_attribute_inheritance_prioritizes_child_class()
+    {
+        $this->extend(
+            (new Extend\Model(Post::class))
+                ->default('answer', 'dont do this'),
+            (new Extend\Model(AbstractEventPost::class))
+                ->default('answer', 42),
+            (new Extend\Model(DiscussionRenamedPost::class))
+                ->default('answer', 'ni!')
+        );
+
+        $this->app();
+
+        $post = new CustomPost;
+
+        $this->assertEquals(42, $post->answer);
+
+        $commentPost = new DiscussionRenamedPost;
+
+        $this->assertEquals('ni!', $commentPost->answer);
+    }
+
     /**
      * @test
      */
@@ -341,3 +415,11 @@ class ModelTest extends TestCase
         $this->assertNotContains('custom', $discussion->getDates());
     }
 }
+
+class CustomPost extends AbstractEventPost
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static $type = 'customPost';
+}