diff --git a/types/node-fetch/index.d.ts b/types/node-fetch/index.d.ts
index 03ae639d26..8883dc1b9d 100644
--- a/types/node-fetch/index.d.ts
+++ b/types/node-fetch/index.d.ts
@@ -4,6 +4,7 @@
 //                 Niklas Lindgren <https://github.com/nikcorg>
 //                 Vinay Bedre <https://github.com/vinaybedre>
 //                 Antonio Román <https://github.com/kyranet>
+//                 Andrew Leedham <https://github.com/AndrewLeedham>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /// <reference types="node" />
@@ -134,7 +135,7 @@ export class Body {
 
 export class FetchError extends Error {
     name: "FetchError";
-    constructor(message: string, type: string, systemError: string);
+    constructor(message: string, type: string, systemError?: string);
     type: string;
     code?: string;
     errno?: string;
diff --git a/types/node-fetch/node-fetch-tests.ts b/types/node-fetch/node-fetch-tests.ts
index d35114f60a..165ac24800 100644
--- a/types/node-fetch/node-fetch-tests.ts
+++ b/types/node-fetch/node-fetch-tests.ts
@@ -1,4 +1,4 @@
-import fetch, { Headers, Request, RequestInit, Response } from 'node-fetch';
+import fetch, { Headers, Request, RequestInit, Response, FetchError } from 'node-fetch';
 import { Agent } from "http";
 
 function test_fetchUrlWithOptions() {
@@ -82,3 +82,8 @@ function test_isRedirect() {
     fetch.isRedirect(301);
     fetch.isRedirect(201);
 }
+
+function test_FetchError() {
+    new FetchError('message', 'type', 'systemError');
+    new FetchError('message', 'type');
+}