diff --git a/codex-rs/app-server/tests/suite/v2/turn_start.rs b/codex-rs/app-server/tests/suite/v2/turn_start.rs
index d41ca2610b..6d66edd3d3 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -749,13 +749,17 @@ async fn turn_start_rejects_combined_oversized_text_input() -> Result<()> {
 #[tokio::test]
 async fn turn_start_rejects_invalid_permission_profile_before_starting_turn() -> Result<()> {
     let codex_home = TempDir::new()?;
-    let unsupported_write_root = TempDir::new()?;
+    let disallowed_write_root = TempDir::new()?;
     create_config_toml(
         codex_home.path(),
         "http://localhost/unused",
         "never",
         &BTreeMap::from([(Feature::Personality, true)]),
     )?;
+    std::fs::write(
+        codex_home.path().join("managed_config.toml"),
+        "sandbox_mode = \"read-only\"\n",
+    )?;
 
     let mut mcp = McpProcess::new(codex_home.path()).await?;
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
@@ -772,7 +776,7 @@ async fn turn_start_rejects_invalid_permission_profile_before_starting_turn() ->
     )
     .await??;
     let ThreadStartResponse { thread, .. } = to_response::<ThreadStartResponse>(thread_resp)?;
-    let unsupported_write_root = AbsolutePathBuf::from_absolute_path(unsupported_write_root.path())
+    let disallowed_write_root = AbsolutePathBuf::from_absolute_path(disallowed_write_root.path())
         .expect("tempdir path should be absolute");
 
     let turn_req = mcp
@@ -787,7 +791,7 @@ async fn turn_start_rejects_invalid_permission_profile_before_starting_turn() ->
                 file_system: PermissionProfileFileSystemPermissions::Restricted {
                     entries: vec![FileSystemSandboxEntry {
                         path: FileSystemPath::Path {
-                            path: unsupported_write_root,
+                            path: disallowed_write_root,
                         },
                         access: FileSystemAccessMode::Write,
                     }],
@@ -806,9 +810,9 @@ async fn turn_start_rejects_invalid_permission_profile_before_starting_turn() ->
     assert_eq!(err.error.code, INVALID_REQUEST_ERROR_CODE);
     assert!(err.error.message.contains("invalid turn context override"));
     assert!(
-        err.error
-            .message
-            .contains("filesystem writes outside the workspace root")
+        err.error.message.contains("allowed set [ReadOnly]"),
+        "unexpected error message: {}",
+        err.error.message
     );
     let turn_started = tokio::time::timeout(
         std::time::Duration::from_millis(250),