diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2314a391c3..bce737a293 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-RC1-42119';
+$wp_version = '4.9-RC1-42120';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
diff --git a/wp-includes/wp-db.php b/wp-includes/wp-db.php
index 04792d4db4..19f79c42b0 100644
--- a/wp-includes/wp-db.php
+++ b/wp-includes/wp-db.php
@@ -1946,7 +1946,7 @@ class wpdb {
 			// If ext/hash is not present, compat.php's hash_hmac() does not support sha256.
 			$algo = function_exists( 'hash' ) ? 'sha256' : 'sha1';
 			// Old WP installs may not have AUTH_SALT defined.
-			$salt = defined( 'AUTH_SALT' ) ? AUTH_SALT : (string) rand();
+			$salt = defined( 'AUTH_SALT' ) && AUTH_SALT ? AUTH_SALT : (string) rand();
 
 			$placeholder = '{' . hash_hmac( $algo, uniqid( $salt, true ), $salt ) . '}';
 		}