diff --git a/wp-includes/class-wp-editor.php b/wp-includes/class-wp-editor.php
index 7de08a7327..3dae85302d 100644
--- a/wp-includes/class-wp-editor.php
+++ b/wp-includes/class-wp-editor.php
@@ -1284,6 +1284,7 @@ final class _WP_Editors {
 				'Link options'                         => __( 'Link options' ), // Tooltip for the 'link options' button in the inline link dialog
 				'Visual'                               => _x( 'Visual', 'Name for the Visual editor tab' ), // Editor switch tab label
 				'Text'                                 => _x( 'Text', 'Name for the Text editor tab (formerly HTML)' ), // Editor switch tab label
+				'Add Media'                            => array( __( 'Add Media' ), 'accessM' ), // Tooltip for the 'Add Media' button in the Gutenberg Classic block
 
 				// Shortcuts help modal
 				'Keyboard Shortcuts'                   => array( __( 'Keyboard Shortcuts' ), 'accessH' ),
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7976b804ee..9fa203cce3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-44397';
+$wp_version = '5.1-alpha-44398';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.