diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index 524be63af5..3b43560d37 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -2179,12 +2179,12 @@ async fn try_run_turn(
         .or_cancel(&cancellation_token)
         .await??;
 
-    let tool_runtime = ToolCallRuntime::new(
+    let tool_runtime = Arc::new(ToolCallRuntime::new(
         Arc::clone(&router),
         Arc::clone(&sess),
         Arc::clone(&turn_context),
         Arc::clone(&turn_diff_tracker),
-    );
+    ));
     let mut in_flight: FuturesUnordered<BoxFuture<CodexResult<ResponseInputItem>>> =
         FuturesUnordered::new();
     let mut responses: Vec<ResponseInputItem> = Vec::new();
@@ -2225,7 +2225,7 @@ async fn try_run_turn(
                         handle_output_item_done(
                             &sess,
                             &turn_context,
-                            &tool_runtime,
+                            Arc::clone(&tool_runtime),
                             item,
                             previously_active_item,
                             &mut in_flight,
diff --git a/codex-rs/core/src/codex/turn_event.rs b/codex-rs/core/src/codex/turn_event.rs
index ce4b996f86..8b4524b2b5 100644
--- a/codex-rs/core/src/codex/turn_event.rs
+++ b/codex-rs/core/src/codex/turn_event.rs
@@ -1,30 +1,37 @@
+use std::pin::Pin;
 use std::sync::Arc;
 
-use futures::future::BoxFuture;
 use futures::stream::FuturesUnordered;
 use tokio_util::sync::CancellationToken;
 
+use super::CodexErr;
+use super::CodexResult;
+use super::Session;
 use super::ToolRouter;
-use super::{CodexErr, CodexResult, Session, TurnContext, TurnItem};
+use super::TurnContext;
+use super::TurnItem;
 use crate::function_tool::FunctionCallError;
 use crate::parse_turn_item;
 use codex_protocol::models::FunctionCallOutputPayload;
 use codex_protocol::models::ResponseInputItem;
 use codex_protocol::models::ResponseItem;
-use futures::FutureExt;
+use futures::Future;
 use tracing::debug;
 
 /// Handle a completed output item from the model stream, recording it and
 /// queuing any tool execution futures. This records items immediately so
 /// history and rollout stay in sync even if the turn is later cancelled.
+pub(super) type InFlightFuture<'f> =
+    Pin<Box<dyn Future<Output = CodexResult<ResponseInputItem>> + Send + 'f>>;
+
 #[allow(clippy::too_many_arguments)]
 pub(super) async fn handle_output_item_done(
     sess: &Arc<Session>,
     turn_context: &Arc<TurnContext>,
-    tool_runtime: &super::ToolCallRuntime,
+    tool_runtime: Arc<super::ToolCallRuntime>,
     item: ResponseItem,
     previously_active_item: Option<TurnItem>,
-    in_flight: &mut FuturesUnordered<BoxFuture<'static, CodexResult<ResponseInputItem>>>,
+    in_flight: &mut FuturesUnordered<InFlightFuture<'_>>,
     responses: &mut Vec<ResponseInputItem>,
     last_agent_message: &mut Option<String>,
     cancellation_token: CancellationToken,
@@ -39,23 +46,22 @@ pub(super) async fn handle_output_item_done(
 
             let sess_for_output: Arc<Session> = Arc::clone(sess);
             let turn_for_output: Arc<TurnContext> = Arc::clone(turn_context);
-            let runtime = tool_runtime.clone();
+            let tool_runtime = Arc::clone(&tool_runtime);
 
-            in_flight.push(
-                async move {
-                    let response_input = runtime.handle_tool_call(call, cancellation_token).await?;
-                    if let Some(response_item) = response_input_to_response_item(&response_input) {
-                        sess_for_output
-                            .record_conversation_items(
-                                turn_for_output.as_ref(),
-                                std::slice::from_ref(&response_item),
-                            )
-                            .await;
-                    }
-                    Ok(response_input)
+            in_flight.push(Box::pin(async move {
+                let response_input = tool_runtime
+                    .handle_tool_call(call, cancellation_token)
+                    .await?;
+                if let Some(response_item) = response_input_to_response_item(&response_input) {
+                    sess_for_output
+                        .record_conversation_items(
+                            turn_for_output.as_ref(),
+                            std::slice::from_ref(&response_item),
+                        )
+                        .await;
                 }
-                .boxed(),
-            );
+                Ok(response_input)
+            }));
         }
         Ok(None) => {
             if let Some(turn_item) = handle_non_tool_response_item(&item).await {
diff --git a/codex-rs/core/src/tools/parallel.rs b/codex-rs/core/src/tools/parallel.rs
index 971ea934d8..33dc42b936 100644
--- a/codex-rs/core/src/tools/parallel.rs
+++ b/codex-rs/core/src/tools/parallel.rs
@@ -17,7 +17,6 @@ use crate::tools::router::ToolRouter;
 use codex_protocol::models::FunctionCallOutputPayload;
 use codex_protocol::models::ResponseInputItem;
 
-#[derive(Clone)]
 pub(crate) struct ToolCallRuntime {
     router: Arc<ToolRouter>,
     session: Arc<Session>,