diff --git a/src/types.ts b/src/types.ts
index cd77b7f..c33864c 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -190,6 +190,7 @@ export interface ApiOrder extends ApiStarkwareSigned {
   cancelId?: string;
   triggerPrice?: string;
   trailingPercent?: string;
+  reduceOnly?: string;
 }
 
 export interface ApiWithdrawal extends ApiStarkwareSigned {