diff --git a/packages/block-library/src/navigation-link/edit.js b/packages/block-library/src/navigation-link/edit.js
index a52349c1580234..fda1268715c328 100644
--- a/packages/block-library/src/navigation-link/edit.js
+++ b/packages/block-library/src/navigation-link/edit.js
@@ -261,6 +261,9 @@ export default function NavigationLinkEdit( {
 	useEffect( () => {
 		// If block has inner blocks, transform to Submenu.
 		if ( hasChildren ) {
+			// This side-effect should not create an undo level as those should
+			// only be created via user interactions.
+			__unstableMarkNextChangeAsNotPersistent();
 			transformToSubmenu();
 		}
 	}, [ hasChildren ] );
diff --git a/packages/block-library/src/navigation-submenu/edit.js b/packages/block-library/src/navigation-submenu/edit.js
index bfb830a9caed2a..866333a061de84 100644
--- a/packages/block-library/src/navigation-submenu/edit.js
+++ b/packages/block-library/src/navigation-submenu/edit.js
@@ -358,6 +358,9 @@ export default function NavigationSubmenuEdit( {
 	useEffect( () => {
 		// If block becomes empty, transform to Navigation Link.
 		if ( ! hasChildren && prevHasChildren ) {
+			// This side-effect should not create an undo level as those should
+			// only be created via user interactions.
+			__unstableMarkNextChangeAsNotPersistent();
 			transformToLink();
 		}
 	}, [ hasChildren, prevHasChildren ] );