diff --git a/wp-includes/cache.php b/wp-includes/cache.php
index e7984ebda1..1af29d5f65 100644
--- a/wp-includes/cache.php
+++ b/wp-includes/cache.php
@@ -323,7 +323,7 @@ class WP_Object_Cache {
 	 * The blog prefix to prepend to keys in non-global groups.
 	 *
 	 * @since 3.5.0
-	 * @var int
+	 * @var string
 	 */
 	private $blog_prefix;