diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 482e5521c9..19fdbbfd68 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -2739,7 +2739,7 @@ function _wp_json_convert_string( $string ) {
 			return mb_convert_encoding( $string, 'UTF-8', 'UTF-8' );
 		}
 	} else {
-		return wp_check_invalid_utf8( $data, true );
+		return wp_check_invalid_utf8( $string, true );
 	}
 }
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e4ff6f0382..93ee3e08ce 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-alpha-30161';
+$wp_version = '4.1-alpha-30162';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.