diff --git a/src/lib.rs b/src/lib.rs
index c967ef3..7efd7f3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -246,6 +246,9 @@ impl Account {
         Ok(Order {
             account: self.inner.clone(),
             nonce,
+            // Order of fields matters! We return errors from Problem::check 
+            // before emitting an error if there is no order url. Or the
+            // simple no url error hides the causing error in `Problem::check`.
             state: Problem::check::<OrderState>(rsp).await?,
             url: order_url.ok_or("no order URL found")?,
         })