diff --git a/extensions/mentions/src/Formatter/FormatPostMentions.php b/extensions/mentions/src/Formatter/FormatPostMentions.php
index 992dca15073..35759f55d2b 100644
--- a/extensions/mentions/src/Formatter/FormatPostMentions.php
+++ b/extensions/mentions/src/Formatter/FormatPostMentions.php
@@ -12,6 +12,7 @@
 use Flarum\Discussion\Discussion;
 use Flarum\Http\SlugManager;
 use Flarum\Locale\TranslatorInterface;
+use Flarum\Post\Post;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use s9e\TextFormatter\Renderer;
 use s9e\TextFormatter\Utils;
@@ -24,12 +25,22 @@ public function __construct(
     ) {
     }
 
-    public function __invoke(Renderer $renderer, mixed $context, ?string $xml, Request $request = null): string
+    /**
+     * Configure rendering for post mentions.
+     *
+     * @param \s9e\TextFormatter\Renderer $renderer
+     * @param mixed $context
+     * @param string $xml
+     * @param \Psr\Http\Message\ServerRequestInterface|null $request
+     * @return string $xml to be rendered
+     */
+    public function __invoke(Renderer $renderer, $context, $xml, Request $request = null)
     {
-        $post = $context;
+        return Utils::replaceAttributes($xml, 'POSTMENTION', function ($attributes) use ($context) {
+            $post = (($context && isset($context->getRelations()['mentionsPosts'])) || $context instanceof Post)
+                ? $context->mentionsPosts->find($attributes['id'])
+                : Post::find($attributes['id']);
 
-        return Utils::replaceAttributes($xml, 'POSTMENTION', function ($attributes) use ($post) {
-            $post = $post->mentionsPosts->find($attributes['id']);
             if ($post && $post->user) {
                 $attributes['displayname'] = $post->user->display_name;
             }
diff --git a/extensions/mentions/src/Formatter/UnparsePostMentions.php b/extensions/mentions/src/Formatter/UnparsePostMentions.php
index 0a5499caf62..fd470c10adc 100644
--- a/extensions/mentions/src/Formatter/UnparsePostMentions.php
+++ b/extensions/mentions/src/Formatter/UnparsePostMentions.php
@@ -9,6 +9,7 @@
 
 namespace Flarum\Mentions\Formatter;
 
+use Flarum\Post\Post;
 use Flarum\Locale\TranslatorInterface;
 use s9e\TextFormatter\Utils;
 
@@ -31,10 +32,11 @@ public function __invoke(mixed $context, string $xml): string
      */
     protected function updatePostMentionTags(mixed $context, string $xml): string
     {
-        $post = $context;
+        return Utils::replaceAttributes($xml, 'POSTMENTION', function ($attributes) use ($context) {
+            $post = (($context && isset($context->getRelations()['mentionsPosts'])) || $context instanceof Post)
+                ? $context->mentionsPosts->find($attributes['id'])
+                : Post::find($attributes['id']);
 
-        return Utils::replaceAttributes($xml, 'POSTMENTION', function ($attributes) use ($post) {
-            $post = $post->mentionsPosts->find($attributes['id']);
             if ($post && $post->user) {
                 $attributes['displayname'] = $post->user->display_name;
             }