diff --git a/src/wp-includes/blocks/navigation-submenu.php b/src/wp-includes/blocks/navigation-submenu.php
index 9138b5a5e08da..50586c42da806 100644
--- a/src/wp-includes/blocks/navigation-submenu.php
+++ b/src/wp-includes/blocks/navigation-submenu.php
@@ -55,6 +55,19 @@ function block_core_navigation_submenu_get_submenu_visibility( $context ) {
 	require_once __DIR__ . '/navigation-link/shared/render-submenu-icon.php';
 }
 
+/**
+ * Renders the submenu icon SVG for the Navigation Submenu block.
+ *
+ * @since 5.9.0
+ * @deprecated 7.0.0 Use block_core_shared_navigation_render_submenu_icon() instead.
+ *
+ * @return string SVG markup for the submenu icon.
+ */
+function block_core_navigation_submenu_render_submenu_icon() {
+	_deprecated_function( __FUNCTION__, '7.0.0', 'block_core_shared_navigation_render_submenu_icon()' );
+	return block_core_shared_navigation_render_submenu_icon();
+}
+
 /**
  * Build an array with CSS classes and inline styles defining the font sizes
  * which will be applied to the navigation markup in the front-end.
diff --git a/tests/phpunit/tests/blocks/navigationSubmenuRenderSubmenuIcon.php b/tests/phpunit/tests/blocks/navigationSubmenuRenderSubmenuIcon.php
new file mode 100644
index 0000000000000..986241ae753c7
--- /dev/null
+++ b/tests/phpunit/tests/blocks/navigationSubmenuRenderSubmenuIcon.php
@@ -0,0 +1,21 @@
+<?php
+/**
+ * Tests for the deprecated block_core_navigation_submenu_render_submenu_icon() shim.
+ *
+ * @package WordPress
+ * @subpackage Blocks
+ *
+ * @group blocks
+ */
+class Tests_Blocks_NavigationSubmenuRenderSubmenuIcon extends WP_UnitTestCase {
+	/**
+	 * @ticket 65287
+	 * @expectedDeprecated block_core_navigation_submenu_render_submenu_icon
+	 */
+	public function test_returns_same_markup_as_shared_helper() {
+		$this->assertSame(
+			block_core_shared_navigation_render_submenu_icon(),
+			block_core_navigation_submenu_render_submenu_icon()
+		);
+	}
+}