diff --git a/lib/sanitize_ext/sanitize_config.rb b/lib/sanitize_ext/sanitize_config.rb
index 3379823cb78..ad310b393a0 100644
--- a/lib/sanitize_ext/sanitize_config.rb
+++ b/lib/sanitize_ext/sanitize_config.rb
@@ -65,7 +65,7 @@ class Sanitize
     end
 
     MASTODON_STRICT = freeze_config(
-      elements: %w(p br span a del pre blockquote code b strong u i em ul ol li ruby rt rp),
+      elements: %w(p br span a del s pre blockquote code b strong u i em ul ol li ruby rt rp),
 
       attributes: {
         'a' => %w(href rel class translate),