diff --git a/src/wp-admin/includes/update.php b/src/wp-admin/includes/update.php
index 29a5f0c783878..03cd1f2bcd263 100644
--- a/src/wp-admin/includes/update.php
+++ b/src/wp-admin/includes/update.php
@@ -120,7 +120,7 @@ function find_core_auto_update() {
  * @return array|false An array of checksums on success, false on failure.
  */
 function get_core_checksums( $version, $locale ) {
-	$http_url = 'http://api.wordpress.org/core/checksums/1.0/?' . http_build_query( compact( 'version', 'locale' ), null, '&' );
+	$http_url = 'http://api.wordpress.org/core/checksums/1.0/?' . http_build_query( compact( 'version', 'locale' ), '', '&' );
 	$url      = $http_url;
 
 	$ssl = wp_http_supports( array( 'ssl' ) );
diff --git a/src/wp-includes/update.php b/src/wp-includes/update.php
index 85d0d4c9a86d0..42ae3ecf3afc1 100644
--- a/src/wp-includes/update.php
+++ b/src/wp-includes/update.php
@@ -143,7 +143,7 @@ function wp_version_check( $extra_stats = array(), $force_check = false ) {
 		$query['channel'] = WP_AUTO_UPDATE_CORE;
 	}
 
-	$url      = 'http://api.wordpress.org/core/version-check/1.7/?' . http_build_query( $query, null, '&' );
+	$url      = 'http://api.wordpress.org/core/version-check/1.7/?' . http_build_query( $query, '', '&' );
 	$http_url = $url;
 	$ssl      = wp_http_supports( array( 'ssl' ) );