diff --git a/lib/types.d.ts b/lib/types.d.ts
index 805c5df24..82a32cdce 100644
--- a/lib/types.d.ts
+++ b/lib/types.d.ts
@@ -78,8 +78,8 @@ export interface Option {
     appid: String;
     channelProfile: number;
     videoEncoderConfig: VideoEncoderConfig;
-    dualStream: boolean;
-    mode: number;
+    dualStream?: boolean;
+    mode?: number;
     clientRole: number;
     audioProfile: number;
     audioScenario: number;
diff --git a/src/types.ts b/src/types.ts
index acc232946..b4443a5b5 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -83,8 +83,8 @@ export interface Option {
   appid: String,
   channelProfile: number,
   videoEncoderConfig: VideoEncoderConfig,
-  dualStream: boolean,
-  mode: number,
+  dualStream?: boolean,
+  mode?: number,
   clientRole: number,
   audioProfile: number,
   audioScenario: number,