diff --git a/codex-rs/tui/src/app.rs b/codex-rs/tui/src/app.rs
index 9c30afdb4b..af1461cf9c 100644
--- a/codex-rs/tui/src/app.rs
+++ b/codex-rs/tui/src/app.rs
@@ -212,6 +212,7 @@ impl App {
     async fn handle_event(&mut self, tui: &mut tui::Tui, event: AppEvent) -> Result<bool> {
         match event {
             AppEvent::NewSession => {
+                self.reset_transcript_history_state();
                 let init = crate::chatwidget::ChatWidgetInit {
                     config: self.config.clone(),
                     frame_requester: tui.frame_requester(),
@@ -367,6 +368,12 @@ impl App {
         Ok(true)
     }
 
+    pub(crate) fn reset_transcript_history_state(&mut self) {
+        self.transcript_cells.clear();
+        self.deferred_history_lines.clear();
+        self.has_emitted_history_lines = false;
+    }
+
     pub(crate) fn token_usage(&self) -> codex_core::protocol::TokenUsage {
         self.chat_widget.token_usage()
     }
diff --git a/codex-rs/tui/src/app_backtrack.rs b/codex-rs/tui/src/app_backtrack.rs
index cbea2c02f7..b730c90a94 100644
--- a/codex-rs/tui/src/app_backtrack.rs
+++ b/codex-rs/tui/src/app_backtrack.rs
@@ -327,6 +327,7 @@ impl App {
         nth_user_message: usize,
         prefill: &str,
     ) {
+        self.reset_transcript_history_state();
         let conv = new_conv.conversation;
         let session_configured = new_conv.session_configured;
         let init = crate::chatwidget::ChatWidgetInit {