diff --git a/_data/site.js b/_data/site.js
index dd14545..7fbea5e 100644
--- a/_data/site.js
+++ b/_data/site.js
@@ -62,11 +62,14 @@ function buildSocialFromFeeds() {
   return links;
 }
 
+// Ensure URL has trailing slash (Mastodon rel="me" verification uses strict string match)
+const siteUrl = (process.env.SITE_URL || "https://example.com").replace(/\/$/, "") + "/";
+
 export default {
   // Basic site info
   name: process.env.SITE_NAME || "My IndieWeb Blog",
-  url: process.env.SITE_URL || "https://example.com",
-  me: process.env.SITE_URL || "https://example.com",
+  url: siteUrl,
+  me: siteUrl,
   locale: process.env.SITE_LOCALE || "en",
   description:
     process.env.SITE_DESCRIPTION ||
@@ -75,7 +78,7 @@ export default {
   // Author info (shown in h-card, about page, etc.)
   author: {
     name: process.env.AUTHOR_NAME || "Blog Author",
-    url: process.env.SITE_URL || "https://example.com",
+    url: siteUrl,
     avatar: process.env.AUTHOR_AVATAR || "/images/default-avatar.svg",
     title: process.env.AUTHOR_TITLE || "",
     bio: process.env.AUTHOR_BIO || "Welcome to my IndieWeb blog.",