diff --git a/codex-rs/tui/src/app/side.rs b/codex-rs/tui/src/app/side.rs
index 30d217471d..9ca7f2b918 100644
--- a/codex-rs/tui/src/app/side.rs
+++ b/codex-rs/tui/src/app/side.rs
@@ -608,8 +608,7 @@ impl App {
         let request_handle = app_server.request_handle();
         let app_event_tx = self.app_event_tx.clone();
         tokio::spawn(async move {
-            let result =
-                super::side_server::unsubscribe_side_thread(request_handle, thread_id).await;
+            let result = super::side_server::cleanup_side_thread(request_handle, thread_id).await;
             app_event_tx.send(AppEvent::SideThreadCleanupFinished(thread_id, result));
         });
     }
diff --git a/codex-rs/tui/src/app/side_server.rs b/codex-rs/tui/src/app/side_server.rs
index 83a8e57c92..f272d2b85a 100644
--- a/codex-rs/tui/src/app/side_server.rs
+++ b/codex-rs/tui/src/app/side_server.rs
@@ -6,6 +6,8 @@ use codex_app_server_protocol::ThreadInjectItemsParams;
 use codex_app_server_protocol::ThreadInjectItemsResponse;
 use codex_app_server_protocol::ThreadUnsubscribeParams;
 use codex_app_server_protocol::ThreadUnsubscribeResponse;
+use codex_app_server_protocol::TurnInterruptParams;
+use codex_app_server_protocol::TurnInterruptResponse;
 
 pub(super) async fn prepare_side_thread(
     request_handle: AppServerRequestHandle,
@@ -56,18 +58,35 @@ pub(super) async fn prepare_side_thread(
     Ok(started)
 }
 
-pub(super) async fn unsubscribe_side_thread(
+pub(super) async fn cleanup_side_thread(
     request_handle: AppServerRequestHandle,
     thread_id: ThreadId,
 ) -> std::result::Result<(), String> {
-    request_handle
+    let interrupt_result = request_handle
+        .request_typed::<TurnInterruptResponse>(ClientRequest::TurnInterrupt {
+            request_id: RequestId::String(format!("side-thread-interrupt-{}", Uuid::new_v4())),
+            params: TurnInterruptParams {
+                thread_id: thread_id.to_string(),
+                turn_id: String::new(),
+            },
+        })
+        .await;
+    let unsubscribe_result = request_handle
         .request_typed::<ThreadUnsubscribeResponse>(ClientRequest::ThreadUnsubscribe {
             request_id: RequestId::String(format!("side-thread-unsubscribe-{}", Uuid::new_v4())),
             params: ThreadUnsubscribeParams {
                 thread_id: thread_id.to_string(),
             },
         })
-        .await
-        .map(|_| ())
-        .map_err(|err| format!("thread/unsubscribe failed in TUI: {err}"))
+        .await;
+    match (interrupt_result, unsubscribe_result) {
+        (Ok(_), Ok(_)) => Ok(()),
+        (Err(interrupt_err), Ok(_)) => Err(format!("turn/interrupt failed: {interrupt_err}")),
+        (Ok(_), Err(unsubscribe_err)) => {
+            Err(format!("thread/unsubscribe failed: {unsubscribe_err}"))
+        }
+        (Err(interrupt_err), Err(unsubscribe_err)) => Err(format!(
+            "turn/interrupt failed: {interrupt_err}; thread/unsubscribe failed: {unsubscribe_err}"
+        )),
+    }
 }