diff --git a/ext/wiki/main.php b/ext/wiki/main.php
index 496f1499..bdf0a692 100644
--- a/ext/wiki/main.php
+++ b/ext/wiki/main.php
@@ -52,11 +52,13 @@ class WikiPage
     public string $title;
     public int $revision;
     public bool $locked;
+    public bool $exists;
     public string $body;
 
     public function __construct(array $row=null)
     {
         //assert(!empty($row));
+        global $database;
 
         if (!is_null($row)) {
             $this->id = (int)$row['id'];
@@ -66,6 +68,7 @@ class WikiPage
             $this->title = $row['title'];
             $this->revision = (int)$row['revision'];
             $this->locked = bool_escape($row['locked']);
+            $this->exists = $database->exists("SELECT id FROM wiki_pages WHERE title = :title", ["title"=>$this->title]);
             $this->body = $row['body'];
         }
     }
@@ -79,6 +82,11 @@ class WikiPage
     {
         return $this->locked;
     }
+
+    public function exists(): bool
+    {
+        return $this->exists;
+    }
 }
 
 abstract class WikiConfig
diff --git a/ext/wiki/theme.php b/ext/wiki/theme.php
index f68623cc..39e52505 100644
--- a/ext/wiki/theme.php
+++ b/ext/wiki/theme.php
@@ -35,6 +35,10 @@ class WikiTheme extends Themelet
             $title_html = $this->tagcategories->getTagHtml($title_html, $tag_category_dict);
         }
 
+        if (!$wiki_page->exists) {
+            $page->set_code(404);
+        }
+
         $page->set_title(html_escape($wiki_page->title));
         $page->set_heading(html_escape($wiki_page->title));
         $page->add_block(new NavBlock());