diff --git a/codex-rs/exec-server/tests/common/exec_server.rs b/codex-rs/exec-server/tests/common/exec_server.rs
index a2476b4fbb0d..fc11f87a054d 100644
--- a/codex-rs/exec-server/tests/common/exec_server.rs
+++ b/codex-rs/exec-server/tests/common/exec_server.rs
@@ -11,6 +11,7 @@ use codex_app_server_protocol::RequestId;
 use codex_utils_cargo_bin::cargo_bin;
 use futures::SinkExt;
 use futures::StreamExt;
+use tempfile::TempDir;
 use tokio::io::AsyncBufReadExt;
 use tokio::io::BufReader;
 use tokio::process::Child;
@@ -26,6 +27,7 @@ const CONNECT_RETRY_INTERVAL: Duration = Duration::from_millis(25);
 const EVENT_TIMEOUT: Duration = Duration::from_secs(5);
 
 pub(crate) struct ExecServerHarness {
+    _codex_home: TempDir,
     child: Child,
     websocket_url: String,
     websocket: tokio_tungstenite::WebSocketStream<
@@ -42,17 +44,20 @@ impl Drop for ExecServerHarness {
 
 pub(crate) async fn exec_server() -> anyhow::Result<ExecServerHarness> {
     let binary = cargo_bin("codex")?;
+    let codex_home = TempDir::new()?;
     let mut child = Command::new(binary);
     child.args(["exec-server", "--listen", "ws://127.0.0.1:0"]);
     child.stdin(Stdio::null());
     child.stdout(Stdio::piped());
     child.stderr(Stdio::inherit());
     child.kill_on_drop(true);
+    child.env("CODEX_HOME", codex_home.path());
     let mut child = child.spawn()?;
 
     let websocket_url = read_listen_url_from_stdout(&mut child).await?;
     let (websocket, _) = connect_websocket_when_ready(&websocket_url).await?;
     Ok(ExecServerHarness {
+        _codex_home: codex_home,
         child,
         websocket_url,
         websocket,