diff --git a/zebra-chain/src/sha256d_writer.rs b/zebra-chain/src/sha256d_writer.rs
index 5e835cdfc..77dbec20c 100644
--- a/zebra-chain/src/sha256d_writer.rs
+++ b/zebra-chain/src/sha256d_writer.rs
@@ -31,3 +31,20 @@ impl Write for Sha256dWriter {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+
+    use std::io::Write;
+
+    use crate::sha256d_writer::Sha256dWriter;
+
+    #[test]
+    fn sha256d_flush() {
+        let preimage = b"foo bar baz";
+        let mut sha_writer = Sha256dWriter::default();
+        let _ = sha_writer.write_all(preimage);
+
+        assert_eq!(sha_writer.flush().unwrap(), ());
+    }
+}
diff --git a/zebra-network/src/protocol/external/codec.rs b/zebra-network/src/protocol/external/codec.rs
index 82e74f4fc..e6d7b2393 100644
--- a/zebra-network/src/protocol/external/codec.rs
+++ b/zebra-network/src/protocol/external/codec.rs
@@ -475,7 +475,7 @@ impl Codec {
         Ok(Message::GetBlocks {
             version: Version(reader.read_u32::<LittleEndian>()?),
             block_locator_hashes: Vec::zcash_deserialize(&mut reader)?,
-            hash_stop: BlockHeaderHash(reader.read_32_bytes()?),
+            hash_stop: BlockHeaderHash::zcash_deserialize(&mut reader)?,
         })
     }
 
@@ -492,7 +492,7 @@ impl Codec {
         Ok(Message::GetHeaders {
             version: Version(reader.read_u32::<LittleEndian>()?),
             block_locator_hashes: Vec::zcash_deserialize(&mut reader)?,
-            hash_stop: BlockHeaderHash(reader.read_32_bytes()?),
+            hash_stop: BlockHeaderHash::zcash_deserialize(&mut reader)?,
         })
     }