diff --git a/app/config/server.ts b/app/config/server.ts
index 9ba0b4d55..92152c546 100644
--- a/app/config/server.ts
+++ b/app/config/server.ts
@@ -12,7 +12,7 @@ declare global {
       BASE_URL?: string;
       OPENAI_ORG_ID?: string; // openai only
 
-      VERCEL?: string;
+      VERCEL?: "1" | undefined;
       BUILD_MODE?: "standalone" | "export";
       BUILD_APP?: string; // is building desktop app