diff --git a/engine/src/dot/http_rpc.rs b/engine/src/dot/http_rpc.rs
index 7e4a1973d7..dfbe92ff2a 100644
--- a/engine/src/dot/http_rpc.rs
+++ b/engine/src/dot/http_rpc.rs
@@ -7,7 +7,7 @@ use jsonrpsee::{
 	core::{client::ClientT, traits::ToRpcParams, Error as JsonRpseeError},
 	http_client::{HttpClient, HttpClientBuilder},
 };
-use reqwest::header::{HeaderMap, AUTHORIZATION};
+use reqwest::header::{HeaderMap, HeaderValue, AUTHORIZATION};
 use serde_json::value::RawValue;
 use sp_core::H256;
 use subxt::{
@@ -22,7 +22,7 @@ use subxt::{
 
 use anyhow::Result;
 use tracing::{error, warn};
-use utilities::{make_periodic_tick, redact_endpoint_secret::SecretUrl};
+use utilities::{const_eval, make_periodic_tick, redact_endpoint_secret::SecretUrl};
 
 use crate::constants::RPC_RETRY_CONNECTION_INTERVAL;
 
@@ -32,12 +32,14 @@ pub struct PolkadotHttpClient(HttpClient);
 
 impl PolkadotHttpClient {
 	pub fn new(url: &SecretUrl) -> Result<Self> {
-		let token = format!("Bearer {}", "TOKEN");
-		let mut headers = HeaderMap::new();
-		headers.insert(AUTHORIZATION, token.parse().unwrap());
-		let client = HttpClientBuilder::default().set_headers(headers).build(url)?;
-
-		Ok(Self(client))
+		Ok(Self(
+			HttpClientBuilder::default()
+				.set_headers(HeaderMap::from_iter([(
+					AUTHORIZATION,
+					const_eval!(HeaderValue, HeaderValue::from_static("Bearer TOKEN")),
+				)]))
+				.build(url)?,
+		))
 	}
 }
 
diff --git a/engine/src/eth/mod.rs b/engine/src/eth/mod.rs
index 56d83c9421..4dc346f549 100644
--- a/engine/src/eth/mod.rs
+++ b/engine/src/eth/mod.rs
@@ -2,7 +2,7 @@ pub mod event;
 pub mod retry_rpc;
 pub mod rpc;
 
-use anyhow::Result;
+use anyhow::{Context, Result};
 
 use futures::FutureExt;
 
@@ -25,6 +25,19 @@ pub struct ConscientiousEthWebsocketBlockHeaderStream {
 	>,
 }
 
+impl ConscientiousEthWebsocketBlockHeaderStream {
+	pub async fn new(web3: web3::Web3<web3::transports::WebSocket>) -> Result<Self> {
+		Ok(Self {
+			stream: Some(
+				web3.eth_subscribe()
+					.subscribe_new_heads()
+					.await
+					.context("Failed to subscribe to new heads with WS Client")?,
+			),
+		})
+	}
+}
+
 impl Drop for ConscientiousEthWebsocketBlockHeaderStream {
 	fn drop(&mut self) {
 		tracing::warn!("Dropping the ETH WS connection");
diff --git a/engine/src/eth/rpc.rs b/engine/src/eth/rpc.rs
index 110b910d52..c2dc4b4a08 100644
--- a/engine/src/eth/rpc.rs
+++ b/engine/src/eth/rpc.rs
@@ -318,14 +318,7 @@ impl ReconnectSubscribeApi for ReconnectSubscriptionClient {
 			bail!("Expected chain id {}, eth ws client returned {client_chain_id}.", self.chain_id)
 		}
 
-		Ok(ConscientiousEthWebsocketBlockHeaderStream {
-			stream: Some(
-				web3.eth_subscribe()
-					.subscribe_new_heads()
-					.await
-					.context("Failed to subscribe to new heads with WS Client")?,
-			),
-		})
+		ConscientiousEthWebsocketBlockHeaderStream::new(web3).await
 	}
 }
 
diff --git a/engine/src/witness/btc/btc_deposits.rs b/engine/src/witness/btc/btc_deposits.rs
index 2fd0ff7e83..36a284d938 100644
--- a/engine/src/witness/btc/btc_deposits.rs
+++ b/engine/src/witness/btc/btc_deposits.rs
@@ -156,7 +156,7 @@ pub mod tests {
 		VerboseTransaction {
 			txid,
 			version: Version::from_consensus(2),
-			locktime: LockTime::Blocks(Height::from_consensus(0).unwrap()),
+			locktime: LockTime::Blocks(Height::ZERO),
 			vin: vec![],
 			vout: tx_outs,
 			fee,
diff --git a/utilities/src/lib.rs b/utilities/src/lib.rs
index 2149b2855f..d57d2e1ec6 100644
--- a/utilities/src/lib.rs
+++ b/utilities/src/lib.rs
@@ -30,6 +30,15 @@ macro_rules! assert_err {
 	};
 }
 
+/// Forces compile evaluation of expression
+#[macro_export]
+macro_rules! const_eval {
+	($t:ty, $e:expr) => {{
+		static X: $t = $e;
+		X.clone()
+	}};
+}
+
 /// Note that the resulting `threshold` is the maximum number
 /// of parties *not* enough to generate a signature,
 /// i.e. at least `t+1` parties are required.