diff --git a/crates/project/src/project_tests.rs b/crates/project/src/project_tests.rs
index 383c1b5c470d32dbee8898cf31bafd3f6b3cff9e..360e4d0c896d52f7b97c5466b97717ce28f9f087 100644
--- a/crates/project/src/project_tests.rs
+++ b/crates/project/src/project_tests.rs
@@ -8,6 +8,7 @@ use language::{
     OffsetRangeExt, Point, ToPoint,
 };
 use lsp::Url;
+use parking_lot::Mutex;
 use pretty_assertions::assert_eq;
 use serde_json::json;
 use std::{cell::RefCell, os::unix, rc::Rc, task::Poll};