diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index 640d1c3f77..b870e87a8f 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -381,6 +381,16 @@ function wp_default_packages_inline_scripts( $scripts ) {
 		'window.wp.oldEditor = window.wp.editor;',
 		'after'
 	);
+
+	// wp-editor module is exposed as window.wp.editor
+	// Problem: there is quite some code expecting window.wp.oldEditor object available under window.wp.editor
+	// Solution: fuse the two objects together to maintain backward compatibility
+	// For more context, see https://github.com/WordPress/gutenberg/issues/33203
+	$scripts->add_inline_script(
+		'wp-editor',
+		'Object.assign( window.wp.editor, window.wp.oldEditor );',
+		'after'
+	);
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 20530f337e..3c4976b855 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-RC2-51386';
+$wp_version = '5.8-RC2-51392';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.