diff --git a/packages/hydrooj/src/settings.ts b/packages/hydrooj/src/settings.ts
index 71a8cf546..f333e1b51 100644
--- a/packages/hydrooj/src/settings.ts
+++ b/packages/hydrooj/src/settings.ts
@@ -2,7 +2,7 @@ import yaml from 'js-yaml';
 import { nanoid } from 'nanoid';
 import Schema from 'schemastery';
 import { Logger } from './logger';
-import { NestKeys } from './typeutils';
+import { Flatten } from './typeutils';
 
 const defaultPath = process.env.CI ? '/tmp/file'
     : process.env.DEFAULT_STORE_PATH || '/data/file/hydro';
@@ -80,7 +80,7 @@ export async function setConfig(key: string, value: any) {
 
 export function requestConfig<T, S>(s: Schema<T, S>): {
     config: ReturnType<Schema<T, S>>,
-    setConfig: (key: NestKeys<ReturnType<Schema<T, S>>>, value: any) => Promise<void>,
+    setConfig: (key: keyof Flatten<ReturnType<Schema<T, S>>> & string, value: any) => Promise<void>,
 } {
     SystemSettings.push(s);
     let curValue = s(systemConfig);
diff --git a/packages/hydrooj/src/typeutils.ts b/packages/hydrooj/src/typeutils.ts
index 958930630..383787525 100644
--- a/packages/hydrooj/src/typeutils.ts
+++ b/packages/hydrooj/src/typeutils.ts
@@ -1,12 +1,21 @@
+/* eslint-disable @typescript-eslint/indent */
+export type Atomic = number | string | boolean | bigint | symbol | Date | any[];
+export type Values<S> = S[keyof S];
+export type Intersect<U> = (U extends any ? (arg: U) => void : never) extends ((arg: infer I) => void) ? I : never;
 export type NumberKeys<O> = {
     [K in keyof O]: number extends O[K] ? K : never
 }[keyof O];
 export type ArrayKeys<O, P = any> = {
     [K in keyof O]: P[] extends O[K] ? K : never
 }[keyof O];
-export type NestKeys<O, T = any, S = any[]> = O extends object ? O extends S ? never : {
-    [K in keyof O]: (O[K] extends T ? K : never) | `${K & string}.${NestKeys<O[K], T, S | O>}`
-}[keyof O] & string : never;
+type FlatWrap<S, T, P extends string> = { [K in P]?: S } | (S extends T ? never // rule out atomic / recursive types
+    : S extends any[] ? never // rule out array types
+    : string extends keyof S ? never // rule out dict / infinite types
+    : FlatMap<S, T, `${P}.`>);
+type FlatMap<S, T = Atomic, P extends string = ''> = Values<{
+    [K in keyof S & string as `${P}${K}`]: FlatWrap<S[K], S | T, `${P}${K}`>
+}>;
+export type Flatten<S> = Intersect<FlatMap<S>>;
 export type Value<O, V = ''> = {
     [K in keyof O]: V
 };