diff --git a/index.d.ts b/index.d.ts
index a97882aa..dc3e809d 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -348,7 +348,7 @@ export interface AxiosRequestConfig<D = any> {
   httpAgent?: any;
   httpsAgent?: any;
   proxy?: AxiosProxyConfig | false;
-  cancelToken?: CancelToken;
+  cancelToken?: CancelToken | undefined;
   decompress?: boolean;
   transitional?: TransitionalOptions;
   signal?: GenericAbortSignal;