diff --git a/packages/block-library/src/navigation-submenu/index.php b/packages/block-library/src/navigation-submenu/index.php
index 87c7c91481cddb..be6046076e76e1 100644
--- a/packages/block-library/src/navigation-submenu/index.php
+++ b/packages/block-library/src/navigation-submenu/index.php
@@ -255,6 +255,14 @@ function render_block_core_navigation_submenu( $attributes, $content, $block ) {
 			$inner_blocks_html .= $inner_block->render();
 		}
 
+		if ( strpos( $inner_blocks_html, 'current-menu-item' ) ) {
+			$tag_processor = new WP_HTML_Tag_Processor( $html );
+			while ( $tag_processor->next_tag( array( 'class_name' => 'wp-block-navigation-item__content' ) ) ) {
+				$tag_processor->add_class( 'current-menu-ancestor' );
+			}
+			$html = $tag_processor->get_updated_html();
+		}
+
 		$html .= sprintf(
 			'<ul class="wp-block-navigation__submenu-container">%s</ul>',
 			$inner_blocks_html