diff --git a/components/net/cookie_storage.rs b/components/net/cookie_storage.rs
index f1ce7ee3190..73159a35c99 100644
--- a/components/net/cookie_storage.rs
+++ b/components/net/cookie_storage.rs
@@ -11,7 +11,7 @@ use net_traits::CookieSource;
 use std::cmp::Ordering;
 use url::Url;
 
-#[derive(Clone, RustcDecodable, RustcEncodable)]
+#[derive(Clone, Debug, RustcDecodable, RustcEncodable)]
 pub struct CookieStorage {
     version: u32,
     cookies: Vec<Cookie>