diff --git a/codex-rs/core/tests/env_snapshot.rs b/codex-rs/core/tests/env_snapshot.rs
index 92b284b085..81c4607ab6 100644
--- a/codex-rs/core/tests/env_snapshot.rs
+++ b/codex-rs/core/tests/env_snapshot.rs
@@ -1,3 +1,5 @@
+#![allow(clippy::expect_used, clippy::unwrap_used)]
+
 use codex_core::Codex;
 use codex_core::CodexSpawnOk;
 use codex_core::ModelProviderInfo;
@@ -19,8 +21,6 @@ use wiremock::matchers::path;
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn first_turn_includes_environment_snapshot() {
-    #![allow(clippy::unwrap_used)]
-
     if std::env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
         println!(
             "Skipping test because it cannot execute when network is disabled in a Codex sandbox."
@@ -101,3 +101,89 @@ async fn first_turn_includes_environment_snapshot() {
     let second_text = first_input["content"][1]["text"].as_str().unwrap();
     assert_eq!(second_text, "hello");
 }
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn snapshot_is_not_injected_on_second_turn() {
+    if std::env::var(CODEX_SANDBOX_NETWORK_DISABLED_ENV_VAR).is_ok() {
+        println!(
+            "Skipping test because it cannot execute when network is disabled in a Codex sandbox."
+        );
+        return;
+    }
+
+    // Prepare cwd with a couple of files (and a hidden one).
+    let cwd = TempDir::new().unwrap();
+    std::fs::write(cwd.path().join("first.txt"), b"x").unwrap();
+    std::fs::write(cwd.path().join("second.txt"), b"x").unwrap();
+    std::fs::write(cwd.path().join(".dot"), b"x").unwrap();
+
+    // Mock server that accepts two requests and completes both.
+    let server = MockServer::start().await;
+    let sse = load_sse_fixture_with_id("tests/fixtures/completed_template.json", "resp1");
+    let responder = ResponseTemplate::new(200)
+        .insert_header("content-type", "text/event-stream")
+        .set_body_raw(sse, "text/event-stream");
+    Mock::given(method("POST"))
+        .and(path("/v1/responses"))
+        .respond_with(responder)
+        .expect(2)
+        .mount(&server)
+        .await;
+
+    let model_provider = ModelProviderInfo {
+        base_url: Some(format!("{}/v1", server.uri())),
+        ..built_in_model_providers()["openai"].clone()
+    };
+
+    let codex_home = TempDir::new().unwrap();
+    let mut config = load_default_config_for_test(&codex_home);
+    config.model_provider = model_provider;
+    config.cwd = cwd.path().to_path_buf();
+
+    let ctrl_c = std::sync::Arc::new(tokio::sync::Notify::new());
+    let CodexSpawnOk { codex, .. } = Codex::spawn(
+        config,
+        Some(CodexAuth::from_api_key("Test API Key".to_string())),
+        ctrl_c.clone(),
+    )
+    .await
+    .unwrap();
+
+    // First user message.
+    codex
+        .submit(Op::UserInput {
+            items: vec![InputItem::Text {
+                text: "first".into(),
+            }],
+        })
+        .await
+        .unwrap();
+    wait_for_event(&codex, |ev| matches!(ev, EventMsg::TaskComplete(_))).await;
+
+    // Second user message.
+    codex
+        .submit(Op::UserInput {
+            items: vec![InputItem::Text {
+                text: "second".into(),
+            }],
+        })
+        .await
+        .unwrap();
+    wait_for_event(&codex, |ev| matches!(ev, EventMsg::TaskComplete(_))).await;
+
+    // Verify the second request's last user message does not include the environment snapshot.
+    let requests = server.received_requests().await.unwrap();
+    assert!(
+        requests.len() >= 2,
+        "expected two requests to the mock server"
+    );
+    let second_req = &requests[1];
+    let body = second_req.body_json::<serde_json::Value>().unwrap();
+
+    let input = body["input"].as_array().expect("input array");
+    let last = input.last().expect("at least one input item");
+    assert_eq!(last["role"], "user");
+    let last_text = last["content"][0]["text"].as_str().unwrap();
+    // Should be exactly the submitted text, without the snapshot header prefix.
+    assert_eq!(last_text, "second");
+}