diff --git a/wp-admin/includes/post.php b/wp-admin/includes/post.php
index 25ce199677..2df3aa7a98 100644
--- a/wp-admin/includes/post.php
+++ b/wp-admin/includes/post.php
@@ -1334,6 +1334,11 @@ function wp_tiny_mce( $teeny = false ) {
 		$initArray = apply_filters('tiny_mce_before_init', $initArray);
 	}
 
+	if ( empty($initArray['theme_advanced_buttons3']) && !empty($initArray['theme_advanced_buttons4']) ) {
+		$initArray['theme_advanced_buttons3'] = $initArray['theme_advanced_buttons4'];
+		$initArray['theme_advanced_buttons4'] = '';
+	}
+
 	if ( ! isset($concatenate_scripts) )
 		script_concat_settings();