diff --git a/codex-rs/tui/src/tui.rs b/codex-rs/tui/src/tui.rs
index 39849471b5..2b4e67e6af 100644
--- a/codex-rs/tui/src/tui.rs
+++ b/codex-rs/tui/src/tui.rs
@@ -1,6 +1,7 @@
 use std::io::IsTerminal;
 use std::io::Result;
 use std::io::Stdout;
+use std::io::stdin;
 use std::io::stdout;
 use std::pin::Pin;
 use std::sync::Arc;
@@ -131,6 +132,9 @@ pub fn restore() -> Result<()> {
 
 /// Initialize the terminal (inline viewport; history stays in normal scrollback)
 pub fn init() -> Result<Terminal> {
+    if !stdin().is_terminal() {
+        return Err(std::io::Error::other("stdin is not a terminal"));
+    }
     if !stdout().is_terminal() {
         return Err(std::io::Error::other("stdout is not a terminal"));
     }
@@ -490,7 +494,7 @@ impl Tui {
             }
         }
 
-        std::io::stdout().sync_update(|_| {
+        stdout().sync_update(|_| {
             #[cfg(unix)]
             {
                 if let Some(prepared) = prepared_resume.take() {