diff --git a/framework/instruments/src/metrics.rs b/framework/instruments/src/metrics.rs
index 09d9b902..3675cb6e 100644
--- a/framework/instruments/src/metrics.rs
+++ b/framework/instruments/src/metrics.rs
@@ -1,8 +1,10 @@
 use opentelemetry_api::global::meter_with_version;
 use opentelemetry_api::metrics::{Histogram, Unit};
 
+#[allow(unused)]
 pub type OperationDurationMetric = Histogram<f64>;
 
+#[allow(unused)]
 pub fn create_operation_duration_metric() -> OperationDurationMetric {
     meter_with_version(
         "wt.operation",
diff --git a/framework/instruments_derive/src/lib.rs b/framework/instruments_derive/src/lib.rs
index d1abf8e3..22057fe4 100644
--- a/framework/instruments_derive/src/lib.rs
+++ b/framework/instruments_derive/src/lib.rs
@@ -92,7 +92,7 @@ pub fn wind_tunnel_instrument(args: TokenStream, input: TokenStream) -> TokenStr
             .collect::<syn::Result<Vec<Option<_>>>>()
             .unwrap()
             .into_iter()
-            .filter_map(|x| x)
+            .flatten()
             .fold(
                 Punctuated::<Expr, syn::token::Comma>::new(),
                 |mut punct, arg| {
diff --git a/framework/runner/src/shutdown.rs b/framework/runner/src/shutdown.rs
index b32c44c0..25eb8bd5 100644
--- a/framework/runner/src/shutdown.rs
+++ b/framework/runner/src/shutdown.rs
@@ -1,10 +1,10 @@
 use std::{borrow::BorrowMut, sync::Arc};
 
-use parking_lot::Mutex;
 use tokio::{
     signal,
     sync::broadcast::{Receiver, Sender},
 };
+use tokio::sync::Mutex;
 
 #[derive(Debug, Clone)]
 pub(crate) struct ShutdownHandle {
@@ -42,10 +42,15 @@ impl DelegatedShutdownListener {
     /// Point in time check if the shutdown signal has been received. If this returns true then work
     /// be stopped so that the scenario can shut down.
     pub fn should_shutdown(&mut self) -> bool {
-        match self.receiver.lock().try_recv() {
-            Ok(_) => true,
-            Err(tokio::sync::broadcast::error::TryRecvError::Closed) => true,
-            // If the receiver is empty or lagged then we should not shutdown.
+        match self.receiver.try_lock() {
+            Ok(mut guard) => {
+                match guard.try_recv() {
+                    Ok(_) => true,
+                    Err(tokio::sync::broadcast::error::TryRecvError::Closed) => true,
+                    // If the receiver is empty or lagged then we should not shutdown.
+                    Err(_) => false,
+                }
+            }
             Err(_) => false,
         }
     }
@@ -57,6 +62,7 @@ impl DelegatedShutdownListener {
         self.receiver
             .borrow_mut()
             .lock()
+            .await
             .recv()
             .await
             .expect("Failed to receive shutdown signal");