diff --git a/src/main/scala/org/scalajs/dom/extensions/Extensions.scala b/src/main/scala/org/scalajs/dom/extensions/Extensions.scala
index 965e3015d..5d19c5080 100644
--- a/src/main/scala/org/scalajs/dom/extensions/Extensions.scala
+++ b/src/main/scala/org/scalajs/dom/extensions/Extensions.scala
@@ -191,6 +191,7 @@ object Ajax{
       }
     }
     req.open(method, url)
+    req.timeout = timeout
     req.withCredentials = withCredentials
     headers.foreach(x => req.setRequestHeader(x._1, x._2))
     req.send(data)