diff --git a/lib/json_schema.atd b/lib/json_schema.atd
index 83f63f2..7b82bc8 100644
--- a/lib/json_schema.atd
+++ b/lib/json_schema.atd
@@ -39,6 +39,7 @@ type str_format = [
   | Email <json name="email">
   | Idn_email <json name="idn-email">
   | Decimal <json name="decimal">
+  | Bytes <json name="bytes">
   | Field_mask <json name="field-mask">
 ]