diff --git a/src/wp-content/themes/twentytwentyone/functions.php b/src/wp-content/themes/twentytwentyone/functions.php
index 1139c3b659..78edfde4b6 100644
--- a/src/wp-content/themes/twentytwentyone/functions.php
+++ b/src/wp-content/themes/twentytwentyone/functions.php
@@ -140,7 +140,7 @@ if ( ! function_exists( 'twenty_twenty_one_setup' ) ) {
 		}
 
 		// Enqueue editor styles.
-		add_editor_style( $editor_stylesheet_path );
+		add_editor_style( $editor_stylesheet_path, 'replace' );
 
 		// Add custom editor font sizes.
 		add_theme_support(
diff --git a/src/wp-content/themes/twentytwentyone/package.json b/src/wp-content/themes/twentytwentyone/package.json
index 6c43119fcb..bfa1cc75e5 100644
--- a/src/wp-content/themes/twentytwentyone/package.json
+++ b/src/wp-content/themes/twentytwentyone/package.json
@@ -55,6 +55,7 @@
 		"build:style-dark-mode": "sass assets/sass/style-dark-mode.scss:assets/css/style-dark-mode.css --style=expanded --source-map",
 		"build:rtl": "rtlcss style.css style-rtl.css style-dark-mode.css style-dark-mode-rtl.css",
 		"build:dark-rtl": "rtlcss assets/css/style-dark-mode.css assets/css/style-dark-mode-rtl.css",
+		"build:style-editor-rtl": "rtlcss assets/css/style-editor.css assets/css/style-editor-rtl.css",
 		"build:print": "sass assets/sass/07-utilities/print.scss:assets/css/print.css --style=expanded --source-map",
 		"build:ie": "postcss style.css -o assets/css/ie.css",
 		"build:ie-editor": "postcss assets/css/style-editor.css -o assets/css/ie-editor.css",
diff --git a/src/wp-includes/theme.php b/src/wp-includes/theme.php
index 916c836f43..ed63c1989c 100644
--- a/src/wp-includes/theme.php
+++ b/src/wp-includes/theme.php
@@ -2035,14 +2035,17 @@ function wp_update_custom_css_post( $css, $args = array() ) {
  * Since version 3.4 the TinyMCE body has .rtl CSS class.
  * It is a better option to use that class and add any RTL styles to the main stylesheet.
  *
+ * @param array|string $stylesheet Optional. Stylesheet name or array thereof, relative to theme root.
+ *                                 Defaults to 'editor-style.css'
+ * @param string $rtl_mode Optional. Should the rtl stylesheet be loaded instead or in addition to the main stylesheet.
+ *                                 Defaults to 'add'
+ *
  * @since 3.0.0
  *
  * @global array $editor_styles
  *
- * @param array|string $stylesheet Optional. Stylesheet name or array thereof, relative to theme root.
- *                                 Defaults to 'editor-style.css'
  */
-function add_editor_style( $stylesheet = 'editor-style.css' ) {
+function add_editor_style( $stylesheet = 'editor-style.css', $rtl_mode = 'add' ) {
 	global $editor_styles;
 
 	add_theme_support( 'editor-style' );
@@ -2053,6 +2056,10 @@ function add_editor_style( $stylesheet = 'editor-style.css' ) {
 	if ( is_rtl() ) {
 		$rtl_stylesheet = str_replace( '.css', '-rtl.css', $stylesheet[0] );
 		$stylesheet[]   = $rtl_stylesheet;
+
+		if ( $rtl_mode === 'replace' ) {
+			unset( $stylesheet[0] );
+		}
 	}
 
 	$editor_styles = array_merge( $editor_styles, $stylesheet );