diff --git a/site/content/docs/5.1/migration.md b/site/content/docs/5.1/migration.md
index 0d0d7eeab4..f499f4dde9 100644
--- a/site/content/docs/5.1/migration.md
+++ b/site/content/docs/5.1/migration.md
@@ -56,6 +56,7 @@ Your custom Bootstrap CSS builds should now look something like this with a sepa
 ### Key changes
 
 - **Introduced new `$enable-container-classes` option.** Now when opting into the experimental CSS Grid layout, `.container-*` classes will still be compiled, unless this option is set to `false`.
+- **Thicker table dividers are now opt-in.** We've removed the thicker and more difficult to override border between table groups and moved it to an optional class you can apply, `.table-group-divider`. [See the table docs for an example.]({{< docsref "/content/tables#table-group-dividers" >}})
 
 ## Dependencies