diff --git a/crates/tui/src/config/tests.rs b/crates/tui/src/config/tests.rs
index 49f6dbdf70..761667b2cb 100644
--- a/crates/tui/src/config/tests.rs
+++ b/crates/tui/src/config/tests.rs
@@ -3953,6 +3953,8 @@ fn openai_codex_default_model_falls_back_to_codex_model() {
 
 #[test]
 fn direct_provider_ignores_foreign_deepseek_root_default_model() {
+    let _lock = lock_test_env();
+
     let config = Config {
         provider: Some("zai".to_string()),
         default_text_model: Some(DEFAULT_TEXT_MODEL.to_string()),