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 ae74b3432f..fbba052eaf 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -400,7 +400,10 @@ async fn turn_start_emits_thread_scoped_warning_notification_for_trimmed_skills(
     write_test_skill(codex_home.path(), "alpha-skill")?;
     write_test_skill(codex_home.path(), "beta-skill")?;
 
-    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    // Skill loading also checks `$HOME/.agents/skills`, so isolate HOME from host-installed skills.
+    let home_dir = codex_home.path().display().to_string();
+    let mut mcp =
+        McpProcess::new_with_env(codex_home.path(), &[("HOME", Some(home_dir.as_str()))]).await?;
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
 
     let thread_req = mcp