diff --git a/src/core/config.ts b/src/core/config.ts
index 42e11b3..353035e 100644
--- a/src/core/config.ts
+++ b/src/core/config.ts
@@ -54,13 +54,23 @@ export type BaseOptions<R, P extends unknown[]> = GlobalOptions & {
   refreshDeps?: WatchSource<any>[];
   cacheKey?: string;
   queryKey?: (...args: P) => string;
-  onSuccess?: (data: R, params: P) => void;
+  onSuccess: (data: R, params: P) => void;
   onError?: (error: Error, params: P) => void;
 };
 
+const FRPlaceholderType = Symbol('FR');
+export type FRPlaceholderType = typeof FRPlaceholderType;
+
+// temporary fix: https://github.com/AttoJS/vue-request/issues/31
+// When `formatResult` and `onSuccess` are used at the same time
+// the type of the parameter `data` of `onSuccess` is temporarily set to `any`
 export type FormatOptions<R, P extends unknown[], FR> = {
   formatResult: (data: R) => FR;
-} & BaseOptions<FR, P>;
+  onSuccess?: (
+    data: FR extends FRPlaceholderType ? any : FR,
+    params: P,
+  ) => void;
+} & Omit<BaseOptions<FR, P>, 'onSuccess'>;
 
 export type MixinOptions<R, P extends unknown[], FR> =
   | BaseOptions<R, P>
diff --git a/src/useLoadMore.ts b/src/useLoadMore.ts
index 8f57b05..2e47c29 100644
--- a/src/useLoadMore.ts
+++ b/src/useLoadMore.ts
@@ -2,6 +2,7 @@ import { computed, inject, ref, Ref, watchEffect } from 'vue';
 import {
   BaseOptions,
   FormatOptions,
+  FRPlaceholderType,
   getGlobalOptions,
   GlobalOptions,
   GLOBAL_OPTIONS_PROVIDE_KEY,
@@ -59,7 +60,7 @@ function useLoadMore<
 function useLoadMore<
   R,
   P extends unknown[] = any,
-  FR = any,
+  FR = FRPlaceholderType,
   LR extends unknown[] = any[]
 >(
   service: LoadMoreService<R, P, LR>,
diff --git a/src/usePagination.ts b/src/usePagination.ts
index 83ad91f..b7c68af 100644
--- a/src/usePagination.ts
+++ b/src/usePagination.ts
@@ -2,6 +2,7 @@ import { computed, inject, Ref } from 'vue';
 import {
   BaseOptions,
   FormatOptions,
+  FRPlaceholderType,
   getGlobalOptions,
   GlobalOptions,
   GLOBAL_OPTIONS_PROVIDE_KEY,
@@ -47,7 +48,7 @@ export type PaginationMixinOptions<R, P extends unknown[], FR> =
 function usePagination<R, P extends unknown[] = any>(
   service: IService<R, P>,
 ): PaginationResult<R, P>;
-function usePagination<R, P extends unknown[] = any, FR = any>(
+function usePagination<R, P extends unknown[] = any, FR = FRPlaceholderType>(
   service: IService<R, P>,
   options: PaginationFormatOptions<R, P, FR>,
 ): PaginationResult<FR, P>;
diff --git a/src/useRequest.ts b/src/useRequest.ts
index 8969c99..e5b4d69 100644
--- a/src/useRequest.ts
+++ b/src/useRequest.ts
@@ -1,4 +1,9 @@
-import { BaseOptions, FormatOptions, MixinOptions } from './core/config';
+import {
+  BaseOptions,
+  FormatOptions,
+  FRPlaceholderType,
+  MixinOptions,
+} from './core/config';
 import useAsyncQuery, { BaseResult } from './core/useAsyncQuery';
 import generateService from './core/utils/generateService';
 import { IService } from './core/utils/types';
@@ -10,7 +15,7 @@ export interface RequestResult<R, P extends unknown[]>
 function useRequest<R, P extends unknown[] = any>(
   service: IService<R, P>,
 ): RequestResult<R, P>;
-function useRequest<R, P extends unknown[] = any, FR = any>(
+function useRequest<R, P extends unknown[] = any, FR = FRPlaceholderType>(
   service: IService<R, P>,
   options: FormatOptions<R, P, FR>,
 ): RequestResult<FR, P>;