diff --git a/types/src/front/api_handlers/public/assistant.ts b/types/src/front/api_handlers/public/assistant.ts
index 2b6ff4f0ef56..92c898786784 100644
--- a/types/src/front/api_handlers/public/assistant.ts
+++ b/types/src/front/api_handlers/public/assistant.ts
@@ -51,5 +51,5 @@ export const PublicPostConversationsRequestBodySchema = t.intersection([
       t.undefined,
     ]),
   }),
-  t.partial({ isSync: t.union([t.boolean, t.undefined]) }),
+  t.partial({ isSync: t.boolean }),
 ]);