diff --git a/taiga_halo2/src/transaction.rs b/taiga_halo2/src/transaction.rs
index f4c8f01e..4b40b587 100644
--- a/taiga_halo2/src/transaction.rs
+++ b/taiga_halo2/src/transaction.rs
@@ -172,9 +172,11 @@ impl rustler::Encoder for Transaction {
             transaction().encode(env),
             self.shielded_ptx_bundle.encode(env),
             borsh::to_vec(&self.transparent_ptx_bundle)
-                .unwrap_or(vec![])
+                .unwrap_or_default()
+                .encode(env),
+            borsh::to_vec(&self.signature)
+                .unwrap_or_default()
                 .encode(env),
-            borsh::to_vec(&self.signature).unwrap_or(vec![]).encode(env),
         )
             .encode(env)
     }