diff --git a/zebra-consensus/src/checkpoint/list/tests.rs b/zebra-consensus/src/checkpoint/list/tests.rs
index 52b8c4d5d..e3b5b7ce0 100644
--- a/zebra-consensus/src/checkpoint/list/tests.rs
+++ b/zebra-consensus/src/checkpoint/list/tests.rs
@@ -174,14 +174,13 @@ fn checkpoint_list_duplicate_heights_fail() -> Result<(), BoxError> {
 
     // Parse the genesis block
     let mut checkpoint_data = Vec::new();
-    for b in &[&zebra_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..]] {
-        let block = Arc::<Block>::zcash_deserialize(*b)?;
-        let hash = block.hash();
-        checkpoint_data.push((
-            block.coinbase_height().expect("test block has height"),
-            hash,
-        ));
-    }
+    let block =
+        Arc::<Block>::zcash_deserialize(&zebra_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..])?;
+    let hash = block.hash();
+    checkpoint_data.push((
+        block.coinbase_height().expect("test block has height"),
+        hash,
+    ));
 
     // Then add some fake entries with duplicate heights
     checkpoint_data.push((block::Height(1), block::Hash([0xaa; 32])));
@@ -202,14 +201,13 @@ fn checkpoint_list_duplicate_hashes_fail() -> Result<(), BoxError> {
 
     // Parse the genesis block
     let mut checkpoint_data = Vec::new();
-    for b in &[&zebra_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..]] {
-        let block = Arc::<Block>::zcash_deserialize(*b)?;
-        let hash = block.hash();
-        checkpoint_data.push((
-            block.coinbase_height().expect("test block has height"),
-            hash,
-        ));
-    }
+    let block =
+        Arc::<Block>::zcash_deserialize(&zebra_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..])?;
+    let hash = block.hash();
+    checkpoint_data.push((
+        block.coinbase_height().expect("test block has height"),
+        hash,
+    ));
 
     // Then add some fake entries with duplicate hashes
     checkpoint_data.push((block::Height(1), block::Hash([0xcc; 32])));
diff --git a/zebra-network/src/protocol/external/codec.rs b/zebra-network/src/protocol/external/codec.rs
index 36e0a9718..c06724f58 100644
--- a/zebra-network/src/protocol/external/codec.rs
+++ b/zebra-network/src/protocol/external/codec.rs
@@ -633,17 +633,23 @@ impl Codec {
     }
 
     fn read_filterload<R: Read>(&self, mut reader: R, body_len: usize) -> Result<Message, Error> {
-        const MAX_FILTERLOAD_LENGTH: usize = 36000;
-        const FILTERLOAD_REMAINDER_LENGTH: usize = 4 + 4 + 1;
+        // The maximum length of a filter.
+        const MAX_FILTERLOAD_FILTER_LENGTH: usize = 36000;
 
-        if !(FILTERLOAD_REMAINDER_LENGTH <= body_len
-            && body_len <= FILTERLOAD_REMAINDER_LENGTH + MAX_FILTERLOAD_LENGTH)
-        {
+        // The data length of the fields:
+        // hash_functions_count + tweak + flags.
+        const FILTERLOAD_FIELDS_LENGTH: usize = 4 + 4 + 1;
+
+        // The maximum length of a filter message's data.
+        const MAX_FILTERLOAD_MESSAGE_LENGTH: usize =
+            MAX_FILTERLOAD_FILTER_LENGTH + FILTERLOAD_FIELDS_LENGTH;
+
+        if !(FILTERLOAD_FIELDS_LENGTH..=MAX_FILTERLOAD_MESSAGE_LENGTH).contains(&body_len) {
             return Err(Error::Parse("Invalid filterload message body length."));
         }
 
-        // Memory Denial of Service: we just limited the untrusted parsed length
-        let filter_length: usize = body_len - FILTERLOAD_REMAINDER_LENGTH;
+        // Memory Denial of Service: we just checked the untrusted parsed length
+        let filter_length: usize = body_len - FILTERLOAD_FIELDS_LENGTH;
         let filter_bytes = zcash_deserialize_bytes_external_count(filter_length, &mut reader)?;
 
         Ok(Message::FilterLoad {