diff --git a/index.d.ts b/index.d.ts
index f934886659..8490672664 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -82,6 +82,7 @@ export interface AxiosError<T = any> extends Error {
   request?: any;
   response?: AxiosResponse<T>;
   isAxiosError: boolean;
+  toJSON: () => object;
 }
 
 export interface AxiosPromise<T = any> extends Promise<AxiosResponse<T>> {