diff --git a/wp-admin/includes/upgrade.php b/wp-admin/includes/upgrade.php
index 96997518a1..8c3fc97cf1 100644
--- a/wp-admin/includes/upgrade.php
+++ b/wp-admin/includes/upgrade.php
@@ -2273,9 +2273,12 @@ function upgrade_590() {
 
 	if ( $wp_current_db_version < 51917 ) {
 		$crons = _get_cron_array();
-		// Remove errant `false` values, see #53950.
-		$crons = array_filter( $crons );
-		_set_cron_array( $crons );
+
+		if ( $crons && is_array( $crons ) ) {
+			// Remove errant `false` values, see #53950.
+			$crons = array_filter( $crons );
+			_set_cron_array( $crons );
+		}
 	}
 }
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a9b3551496..0e5d4403a3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-alpha-52655';
+$wp_version = '6.0-alpha-52656';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.