diff --git a/source/framework/master/validation.php b/source/framework/master/validation.php
index 2d50431ed97..c2dd5ae0a55 100644
--- a/source/framework/master/validation.php
+++ b/source/framework/master/validation.php
@@ -11,6 +11,7 @@
     'alpha'           => 'The :attribute field must only contain letters.',
     'alpha_dash'      => 'The :attribute field must only contain letters, numbers, dashes, and underscores.',
     'alpha_num'       => 'The :attribute field must only contain letters and numbers.',
+    'any_of'          => 'The :attribute field is invalid.',
     'array'           => 'The :attribute field must be an array.',
     'ascii'           => 'The :attribute field must only contain single-byte alphanumeric characters and symbols.',
     'attributes'      => [],