diff --git a/exercises/structs/structs3.rs b/exercises/structs/structs3.rs
index 0b3615f..3536a45 100644
--- a/exercises/structs/structs3.rs
+++ b/exercises/structs/structs3.rs
@@ -78,5 +78,6 @@ mod tests {
         let package = Package::new(sender_country, recipient_country, 1500);
 
         assert_eq!(package.get_fees(cents_per_gram), 4500);
+        assert_eq!(package.get_fees(cents_per_gram * 2), 9000);
     }
 }