diff --git a/sites/main-site/src/pages/join.astro b/sites/main-site/src/pages/join.astro
index 6bfba02c7c..e4ed57dc7c 100644
--- a/sites/main-site/src/pages/join.astro
+++ b/sites/main-site/src/pages/join.astro
@@ -145,7 +145,7 @@ const headings = [
             ><i class="fab fa-slack"></i> Get an invite to nf-core Slack</a
         >
     </p>
-    <div class="alert alert-secondary text-center">
+    <div class="alert alert-secondary text-center small">
         If the invite link doesn't work, please email us at
         <a href="mailto:core@nf-co.re">core@nf-co.re</a> so that we can update it. Thanks!
     </div>