diff --git a/.changeset/remove-nav-item-blueprint-test-utils.md b/.changeset/remove-nav-item-blueprint-test-utils.md
index ef553119b5..b480688b07 100644
--- a/.changeset/remove-nav-item-blueprint-test-utils.md
+++ b/.changeset/remove-nav-item-blueprint-test-utils.md
@@ -1,5 +1,9 @@
 ---
-'@backstage/frontend-test-utils': patch
+'@backstage/frontend-test-utils': minor
 ---
 
-Disabled the app nav extension in `renderInTestApp`, removing the legacy nav-item rendering stub.
+**BREAKING**: `renderInTestApp` no longer renders a sidebar or legacy `nav-item` extensions. The app nav extension is now disabled in the minimal test app shell, along with the layout and routes extensions.
+
+If your tests passed `features` containing `nav-item` extensions and asserted on links or labels in that stub sidebar, switch to `renderTestApp` instead — it uses the real app shell and discovers nav items from page extensions.
+
+If you only use `renderInTestApp` to mount a component with APIs or route refs, there is no change.