diff --git a/front/src/iframe_api.ts b/front/src/iframe_api.ts
index 0264d0a6..9fa204b9 100644
--- a/front/src/iframe_api.ts
+++ b/front/src/iframe_api.ts
@@ -22,7 +22,7 @@ interface WorkAdventureApi {
     openPopup(targetObject: string, message: string, buttons: ButtonDescriptor[]): Popup;
     openTab(url : string): void;
     goToPage(url : string): void;
-    openCoWebSite(url : string, allowApi: boolean, allowPolicy: string): void;
+    openCoWebSite(url : string, allowApi?: boolean, allowPolicy?: string): void;
     closeCoWebSite(): void;
     disablePlayerControls(): void;
     restorePlayerControls(): void;