diff --git a/_includes/components/widgets/social-activity.njk b/_includes/components/widgets/social-activity.njk
index d2b16c9..c545548 100644
--- a/_includes/components/widgets/social-activity.njk
+++ b/_includes/components/widgets/social-activity.njk
@@ -1,7 +1,8 @@
 {# Social Feed Widget - Tabbed Bluesky/Mastodon #}
 {% if (blueskyFeed and blueskyFeed.length) or (mastodonFeed and mastodonFeed.length) %}
 <is-land on:visible>
-<div class="widget" x-data="{ activeTab: 'bluesky' }">
+{% set defaultSocialTab = "mastodon" if mastodonFeed and mastodonFeed.length else "bluesky" %}
+<div class="widget" x-data="{ activeTab: '{{ defaultSocialTab }}' }">
   <h3 class="widget-title">Social Activity</h3>
 
   {# Tab buttons #}
diff --git a/theme/_includes/components/widgets/social-activity.njk b/theme/_includes/components/widgets/social-activity.njk
index 21910a5..df1987c 100644
--- a/theme/_includes/components/widgets/social-activity.njk
+++ b/theme/_includes/components/widgets/social-activity.njk
@@ -1,7 +1,8 @@
 {# Social Feed Widget - Tabbed Bluesky/Mastodon #}
 {% if (blueskyFeed and blueskyFeed.length) or (mastodonFeed and mastodonFeed.length) %}
 <is-land on:visible>
-<div class="widget" x-data="{ activeTab: 'bluesky' }">
+{% set defaultSocialTab = "mastodon" if mastodonFeed and mastodonFeed.length else "bluesky" %}
+<div class="widget" x-data="{ activeTab: '{{ defaultSocialTab }}' }">
   <h3 class="widget-title">Social Activity</h3>
 
   {# Tab buttons #}