diff --git a/ui/src/plugins/advent22.ts b/ui/src/plugins/advent22.ts
index 3d30743..64a6894 100644
--- a/ui/src/plugins/advent22.ts
+++ b/ui/src/plugins/advent22.ts
@@ -24,6 +24,8 @@ export class Advent22 {
     return `//${window.location.hostname}:8000/api`;
   }
 
+  public api_url(): string;
+  public api_url(endpoint: string): string;
   public api_url(endpoint?: string): string {
     if (endpoint === undefined) {
       return this.api_baseurl;