diff --git a/wp-admin/includes/upgrade.php b/wp-admin/includes/upgrade.php
index 1622cab934..5d2e3fc198 100644
--- a/wp-admin/includes/upgrade.php
+++ b/wp-admin/includes/upgrade.php
@@ -86,6 +86,15 @@ function wp_install( $blog_title, $user_name, $user_email, $public, $deprecated
 
 	wp_cache_flush();
 
+	/**
+	 * Fires after a site is fully installed.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param WP_User $user The site owner.
+	 */
+	do_action( 'wp_install', $user );
+
 	return array('url' => $guessurl, 'user_id' => $user_id, 'password' => $user_password, 'password_message' => $message);
 }
 endif;
@@ -317,6 +326,16 @@ function wp_upgrade() {
 		else
 			$wpdb->query( "INSERT INTO {$wpdb->blog_versions} ( `blog_id` , `db_version` , `last_updated` ) VALUES ( '{$wpdb->blogid}', '{$wp_db_version}', NOW());" );
 	}
+
+	/**
+	 * Fires after a site is fully upgraded.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param int $new_db_version The new $wp_db_version.
+	 * @param int $old_db_version The old $wp_db_version.
+	 */
+	do_action( 'wp_upgrade', $wp_db_version, $wp_current_db_version );
 }
 endif;