diff --git a/modules/authfacebook/extlibinc/base_facebook.php b/modules/authfacebook/extlibinc/base_facebook.php
index beffc698908b17f191f5cb2c88a67fa0ccfc8039..f5c14326ba5180a41d7768d25af9cecd4664daba 100644
--- a/modules/authfacebook/extlibinc/base_facebook.php
+++ b/modules/authfacebook/extlibinc/base_facebook.php
@@ -436,7 +436,7 @@ abstract class BaseFacebook
      * return a valid user access token, or false if one is determined
      * to not be available.
      *
-     * @return string A valid user access token, or false if one
+     * @return false|string A valid user access token, or false if one
      *                could not be determined.
      */
     protected function getUserAccessToken()