diff --git a/router/src/url.rs b/router/src/url.rs
index 6215982a..b5d6d8a6 100644
--- a/router/src/url.rs
+++ b/router/src/url.rs
@@ -239,5 +239,13 @@ mod tests {
                 assert!(from_hex(c).is_none())
             }
         }
+
+        let expected = [
+            0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 10, 11, 12, 13, 14, 15,
+        ];
+        for i in 0..hex.len() {
+            println!("{}", hex[i]);
+            assert_eq!(from_hex(hex[i]).unwrap(), expected[i]);
+        }
     }
 }