diff --git a/routes/api/shared_token.ts b/routes/api/shared_token.ts
index f1acb14..836cf0a 100644
--- a/routes/api/shared_token.ts
+++ b/routes/api/shared_token.ts
@@ -53,7 +53,7 @@ export const handler: Handlers = {
             }
             const existed = await exists(flutter_base);
             const host = get_host(req);
-            const base = host + existed ? "/flutter" : "/api/";
+            const base = host + (existed ? "/flutter" : "/api/");
             const token = encodeURIComponent(st.token);
             const url = existed
                 ? `${base}/gallery/${gid}?share=${token}`