diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index d2721cc74634..81b9a086d857 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -923,7 +923,7 @@ impl<'a> PrivateXMLHttpRequestHelpers for JSRef<'a, XMLHttpRequest> {
 
     fn dispatch_response_progress_event(self, type_: DOMString) {
         let len = self.response.borrow().len() as u64;
-        let total = self.response_headers.borrow().get::<ContentLength>().map(|x| {x.len() as u64});
+        let total = self.response_headers.borrow().get::<ContentLength>().map(|x| {**x as u64});
         self.dispatch_progress_event(false, type_, len, total);
     }
     fn set_timeout(self, timeout: u32) {