diff --git a/ui/src/ui/storage.ts b/ui/src/ui/storage.ts
index e8d281755bb..757dc9eab7f 100644
--- a/ui/src/ui/storage.ts
+++ b/ui/src/ui/storage.ts
@@ -1,7 +1,7 @@
 const KEY = "openclaw.control.settings.v1";
 
 import { isSupportedLocale } from "../i18n/index.ts";
-import { inferBasePathFromPathname } from "./navigation.ts";
+import { inferBasePathFromPathname, normalizeBasePath } from "./navigation.ts";
 import type { ThemeMode } from "./theme.ts";
 
 export type UiSettings = {
@@ -21,9 +21,13 @@ export type UiSettings = {
 export function loadSettings(): UiSettings {
   const defaultUrl = (() => {
     const proto = location.protocol === "https:" ? "wss" : "ws";
-    const basePath =
-      (typeof window !== "undefined" && window.__OPENCLAW_CONTROL_UI_BASE_PATH__) ||
-      inferBasePathFromPathname(location.pathname);
+    const configured =
+      typeof window !== "undefined" &&
+      typeof window.__OPENCLAW_CONTROL_UI_BASE_PATH__ === "string" &&
+      window.__OPENCLAW_CONTROL_UI_BASE_PATH__.trim();
+    const basePath = configured
+      ? normalizeBasePath(configured)
+      : inferBasePathFromPathname(location.pathname);
     return `${proto}://${location.host}${basePath}`;
   })();