diff --git a/pallas-traverse/src/block.rs b/pallas-traverse/src/block.rs
index fbeefd3..fc32bf4 100644
--- a/pallas-traverse/src/block.rs
+++ b/pallas-traverse/src/block.rs
@@ -166,9 +166,9 @@ mod tests {
     fn test_iteration() {
         let blocks = vec![
             (include_str!("../../test_data/byron2.block"), 2usize),
-            (include_str!("../../test_data/shelley1.block"), 0),
-            (include_str!("../../test_data/mary1.block"), 0),
-            (include_str!("../../test_data/allegra1.block"), 0),
+            (include_str!("../../test_data/shelley1.block"), 4),
+            (include_str!("../../test_data/mary1.block"), 14),
+            (include_str!("../../test_data/allegra1.block"), 3),
             (include_str!("../../test_data/alonzo1.block"), 5),
         ];
 
diff --git a/pallas-traverse/src/support.rs b/pallas-traverse/src/support.rs
index dbf3da1..2c0b603 100644
--- a/pallas-traverse/src/support.rs
+++ b/pallas-traverse/src/support.rs
@@ -11,8 +11,9 @@ macro_rules! clone_tx_fn {
 
             let success = !block
                 .invalid_transactions
-                .as_ref()?
-                .contains(&(index as u32));
+                .as_ref()
+                .map(|x| x.contains(&(index as u32)))
+                .unwrap_or(false);
 
             let auxiliary_data = block
                 .auxiliary_data_set