diff --git a/wp-admin/includes/class-wp-site-health.php b/wp-admin/includes/class-wp-site-health.php
index 8a6fa79827..6b0a254476 100644
--- a/wp-admin/includes/class-wp-site-health.php
+++ b/wp-admin/includes/class-wp-site-health.php
@@ -1890,7 +1890,7 @@ class WP_Site_Health {
 	 * @return array The test results.
 	 */
 	public function get_test_available_updates_disk_space() {
-		$available_space       = function_exists( 'disk_free_space' ) ? (int) @disk_free_space( WP_CONTENT_DIR . '/upgrade/' ) : false;
+		$available_space       = function_exists( 'disk_free_space' ) ? (int) @disk_free_space( WP_CONTENT_DIR . '/upgrade/' ) : 0;
 		$available_space_in_mb = $available_space / MB_IN_BYTES;
 
 		$result = array(
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 42aa9eefe8..5d1051425c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51897';
+$wp_version = '5.9-alpha-51898';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.