diff --git a/site/posts/2025-04-24-thinking-machines.md b/site/posts/2025-04-24-thinking-machines.md
index 4fc2149..05663c1 100644
--- a/site/posts/2025-04-24-thinking-machines.md
+++ b/site/posts/2025-04-24-thinking-machines.md
@@ -1,5 +1,6 @@
 ---
 title: Thinking machines - some thoughts about large language models
+slug: thinking-machines
 description: "The computers will start thinking, and people will stop."
 ---
 
diff --git a/site/posts/posts.11tydata.js b/site/posts/posts.11tydata.js
index 8faa436..aafc78e 100644
--- a/site/posts/posts.11tydata.js
+++ b/site/posts/posts.11tydata.js
@@ -1,9 +1,10 @@
 module.exports = {
   layout: "post.njk",
-  permalink: "/posts/{{ title | slugify }}/",
+  permalink: "/posts/{{ slug | default:title | slugify }}/",
   tags: ["posts"],
   author: "Joshua Seigler",
   eleventyComputed: {
-    date: "{{ page.date }}"
+    date: "{{ page.date }}",
+    slug: "{{ page.slug }}"
   }
 };