diff --git a/zebra-chain/src/block.rs b/zebra-chain/src/block.rs
index 654ee3e1..b0093658 100644
--- a/zebra-chain/src/block.rs
+++ b/zebra-chain/src/block.rs
@@ -119,6 +119,8 @@ pub struct BlockHeader {
 
 impl ZcashSerialize for BlockHeader {
     fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), SerializationError> {
+        // "The current and only defined block version number for Zcash is 4."
+        writer.write_u32::<LittleEndian>(4)?;
         self.previous_block_hash.zcash_serialize(&mut writer)?;
         writer.write_all(&self.merkle_root_hash.0[..])?;
         writer.write_all(&self.final_sapling_root_hash.0[..])?;
@@ -132,6 +134,13 @@ impl ZcashSerialize for BlockHeader {
 
 impl ZcashDeserialize for BlockHeader {
     fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        // "The current and only defined block version number for Zcash is 4."
+        let version = reader.read_u32::<LittleEndian>()?;
+
+        if version != 4 {
+            return Err(SerializationError::Parse("bad block header"));
+        }
+
         Ok(BlockHeader {
             previous_block_hash: BlockHeaderHash::zcash_deserialize(&mut reader)?,
             merkle_root_hash: MerkleTreeRootHash(reader.read_32_bytes()?),
diff --git a/zebra-chain/src/block/test_vectors.rs b/zebra-chain/src/block/test_vectors.rs
index 43223acd..d167b75d 100644
--- a/zebra-chain/src/block/test_vectors.rs
+++ b/zebra-chain/src/block/test_vectors.rs
@@ -1,5 +1,6 @@
 // Copied from librustzcash
 // From mainnet block 415000.
+// https://explorer.zcha.in/blocks/415000
 pub const HEADER_MAINNET_415000: [u8; 1487] = [
     0x04, 0x00, 0x00, 0x00, 0x52, 0x74, 0xb4, 0x3b, 0x9e, 0x4a, 0xd8, 0xf4, 0x3e, 0x93, 0xf7, 0x84,
     0x63, 0xd2, 0x4d, 0xcf, 0xe5, 0x31, 0xae, 0xb4, 0x71, 0x98, 0x19, 0xf4, 0xf9, 0x7f, 0x7e, 0x03,
diff --git a/zebra-chain/src/block/tests.rs b/zebra-chain/src/block/tests.rs
index f83923a5..9646ffa4 100644
--- a/zebra-chain/src/block/tests.rs
+++ b/zebra-chain/src/block/tests.rs
@@ -81,7 +81,7 @@ fn blockheaderhash_from_blockheader() {
 
     assert_eq!(
         format!("{:?}", hash),
-        "BlockHeaderHash(\"738948d714d44f3040c2b6809ba7dbc8f4ba673dad39fd755ea4aeaa514cc386\")"
+        "BlockHeaderHash(\"e942461f17dd1daea4157df9ba7a2aa5c90a885ac205375a0161f682635da207\")"
     );
 
     let mut bytes = Cursor::new(Vec::new());
@@ -99,9 +99,8 @@ fn blockheaderhash_from_blockheader() {
 
 #[test]
 fn deserialize_blockheader() {
-    // This deserializes without error but the result looks wrong.
     // https://explorer.zcha.in/blocks/415000
-    let header = BlockHeader::zcash_deserialize(&test_vectors::HEADER_MAINNET_415000[..])
+    let _header = BlockHeader::zcash_deserialize(&test_vectors::HEADER_MAINNET_415000[..])
         .expect("blockheader test vector should deserialize");
 }