diff --git a/fetch.js b/fetch.js
index f39a983a..3105a479 100644
--- a/fetch.js
+++ b/fetch.js
@@ -558,13 +558,13 @@ export function fetch(input, init) {
 
     xhr.onerror = function() {
       setTimeout(function() {
-        reject(new TypeError('Network request failed'))
+        reject(new TypeError('Network request ('+request.method+' '+request.url+') failed'))
       }, 0)
     }
 
     xhr.ontimeout = function() {
       setTimeout(function() {
-        reject(new TypeError('Network request timed out'))
+        reject(new TypeError('Network request ('+request.method+' '+request.url+') timed out'))
       }, 0)
     }