diff --git a/zebra-state/src/service/finalized_state.rs b/zebra-state/src/service/finalized_state.rs
index 85d99491..b78a2ec5 100644
--- a/zebra-state/src/service/finalized_state.rs
+++ b/zebra-state/src/service/finalized_state.rs
@@ -246,9 +246,10 @@ impl FinalizedState {
 
             // TODO: sprout and sapling anchors (per block)
 
-            // Consensus-critical bug in zcashd: transactions in the
-            // genesis block are ignored.
-            if block.header.previous_block_hash == block::Hash([0; 32]) {
+            // "A transaction MUST NOT spend an output of the genesis block coinbase transaction.
+            // (There is one such zero-valued output, on each of Testnet and Mainnet .)"
+            // https://zips.z.cash/protocol/protocol.pdf#txnconsensus
+            if block.header.previous_block_hash == GENESIS_PREVIOUS_BLOCK_HASH {
                 return batch;
             }
 
@@ -258,7 +259,6 @@ impl FinalizedState {
             }
 
             // Index each transaction, spent inputs, nullifiers
-            // TODO: move computation into FinalizedBlock as with transparent outputs
             for (transaction_index, (transaction, transaction_hash)) in block
                 .transactions
                 .iter()
diff --git a/zebra-state/src/service/finalized_state/disk_format.rs b/zebra-state/src/service/finalized_state/disk_format.rs
index 4da8886d..fce669e9 100644
--- a/zebra-state/src/service/finalized_state/disk_format.rs
+++ b/zebra-state/src/service/finalized_state/disk_format.rs
@@ -235,7 +235,8 @@ impl IntoDisk for transparent::OutPoint {
 /// Helper trait for inserting (Key, Value) pairs into rocksdb with a consistently
 /// defined format
 pub trait DiskSerialize {
-    /// Serialize and insert the given key and value into a rocksdb column family.
+    /// Serialize and insert the given key and value into a rocksdb column family,
+    /// overwriting any existing `value` for `key`.
     fn zs_insert<K, V>(&mut self, cf: &rocksdb::ColumnFamily, key: K, value: V)
     where
         K: IntoDisk + Debug,