diff --git a/types/FluentJSONSchema.d.ts b/types/FluentJSONSchema.d.ts
index 0589875..a61fb19 100644
--- a/types/FluentJSONSchema.d.ts
+++ b/types/FluentJSONSchema.d.ts
@@ -50,7 +50,9 @@ type FORMATS = {
   URI: 'uri'
   TIME: 'time'
   DATE: 'date'
-  DATE_TIME: 'date-time'
+  DATE_TIME: 'date-time',
+  ISO_TIME: 'iso-time',
+  ISO_DATE_TIME: 'iso-date-time'
 }
 
 export type JSONSchema =
diff --git a/types/FluentJSONSchema.test-d.ts b/types/FluentJSONSchema.test-d.ts
index 9a18a1f..d6bb0e2 100644
--- a/types/FluentJSONSchema.test-d.ts
+++ b/types/FluentJSONSchema.test-d.ts
@@ -43,6 +43,8 @@ const schema = S.object()
   )
   .required()
   .prop('age', S.mixed(['string', 'integer']))
+  .prop('isoTime', S.string().format(S.FORMATS.ISO_TIME))
+  .prop('isoDateTime', S.string().format('iso-date-time'))
   .ifThen(S.object().prop('age', S.string()), S.required(['age']))
   .readOnly()
   .writeOnly(true)