diff --git a/substrate/primitives/src/networks.rs b/substrate/primitives/src/networks.rs
index 285f2947e..64cf7cc2e 100644
--- a/substrate/primitives/src/networks.rs
+++ b/substrate/primitives/src/networks.rs
@@ -95,7 +95,7 @@ impl Decode for NetworkId {
     let kind = input.read_byte()?;
     match kind {
       0 => Ok(Self::Serai),
-      _ => Ok(ExternalNetworkId::decode(input)?.into()),
+      _ => Ok(ExternalNetworkId::decode(&mut [kind].as_slice())?.into()),
     }
   }
 }
@@ -264,7 +264,7 @@ impl Decode for Coin {
     let kind = input.read_byte()?;
     match kind {
       0 => Ok(Self::Serai),
-      _ => Ok(ExternalCoin::decode(input)?.into()),
+      _ => Ok(ExternalCoin::decode(&mut [kind].as_slice())?.into()),
     }
   }
 }
diff --git a/tests/processor/src/tests/batch.rs b/tests/processor/src/tests/batch.rs
index 2428a456a..4a34500ea 100644
--- a/tests/processor/src/tests/batch.rs
+++ b/tests/processor/src/tests/batch.rs
@@ -13,7 +13,7 @@ use serai_client::{
   },
   primitives::{
     crypto::RuntimePublic, Amount, BlockHash, ExternalBalance, ExternalNetworkId, PublicKey,
-    SeraiAddress,
+    SeraiAddress, EXTERNAL_NETWORKS,
   },
   validator_sets::primitives::Session,
 };
@@ -190,9 +190,7 @@ pub(crate) async fn substrate_block(
 
 #[test]
 fn batch_test() {
-  for network in
-    [ExternalNetworkId::Bitcoin, ExternalNetworkId::Ethereum, ExternalNetworkId::Monero]
-  {
+  for network in EXTERNAL_NETWORKS {
     let (coordinators, test) = new_test(network);
 
     test.run(|ops| async move {