diff --git a/web/src/interfaces/Interface.ts b/web/src/interfaces/Interface.ts
index 80ffd51893..3309e580e6 100644
--- a/web/src/interfaces/Interface.ts
+++ b/web/src/interfaces/Interface.ts
@@ -8,7 +8,7 @@ import "../elements/sidebar/SidebarHamburger";
 
 export abstract class Interface extends LitElement {
     @property({type: Boolean})
-    sidebarOpen?: boolean;
+    sidebarOpen: boolean = true;
 
     abstract get sidebar(): SidebarItem[];