diff --git a/src/http-api/fetch.ts b/src/http-api/fetch.ts
index 4285d9248..33a22b64a 100644
--- a/src/http-api/fetch.ts
+++ b/src/http-api/fetch.ts
@@ -39,9 +39,9 @@ interface TypedResponse<T> extends Response {
     json(): Promise<T>;
 }
 
-export type ResponseType<T, O extends IHttpOpts> = O extends undefined
-    ? T
-    : O extends { onlyData: true }
+export type ResponseType<T, O extends IHttpOpts> = O extends { json: false }
+    ? string
+    : O extends { onlyData: true } | undefined
       ? T
       : TypedResponse<T>;
 
@@ -371,7 +371,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
         }
 
         if (this.opts.onlyData) {
-            return json ? res.json() : res.text();
+            return (json ? res.json() : res.text()) as ResponseType<T, O>;
         }
         return res as ResponseType<T, O>;
     }
diff --git a/yarn.lock b/yarn.lock
index f1cbac0ac..fdc2d3f46 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6383,9 +6383,9 @@ typedoc@^0.27.0:
     yaml "^2.6.1"
 
 typescript@^5.4.2:
-  version "5.7.3"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.7.3.tgz#919b44a7dbb8583a9b856d162be24a54bf80073e"
-  integrity sha512-84MVSjMEHP+FQRPy3pX9sTVV/INIex71s9TL2Gm5FG/WG1SqXeKyZ0k7/blY/4FdOzI12CBy1vGc4og/eus0fw==
+  version "5.8.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.8.2.tgz#8170b3702f74b79db2e5a96207c15e65807999e4"
+  integrity sha512-aJn6wq13/afZp/jT9QZmwEjDqqvSGp1VT5GVg+f/t6/oVyrgXM6BY1h9BRh/O5p3PlUPAe+WuiEZOmb/49RqoQ==
 
 uc.micro@^2.0.0, uc.micro@^2.1.0:
   version "2.1.0"