diff --git a/Cargo.lock b/Cargo.lock
index 2ea5f8bfa..b94786b7c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -708,9 +708,9 @@ dependencies = [
 
 [[package]]
 name = "fs4"
-version = "0.8.4"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7e180ac76c23b45e767bd7ae9579bc0bb458618c4bc71835926e098e61d15f8"
+checksum = "ec6fcfb3c0c1d71612528825042261419d5dade9678c39a781e05b63677d9b32"
 dependencies = [
  "rustix",
  "windows-sys 0.52.0",
diff --git a/Cargo.toml b/Cargo.toml
index 54a808b7d..7acf8fbcf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -87,7 +87,7 @@ log = "0.4.20"
 env_logger = "0.10.0"
 thiserror = "1.0"
 test-log = "0.2"
-fs4 = { version = "0.8.3", features = ["sync"] }
+fs4 = { version = "0.10.0", features = ["sync"] }
 ariadne = { version = "0.4.1", features = ["auto-color"] }
 clap_complete = { version = "4.5.4" }
 schemars = "0.8"
diff --git a/crates/moonbuild/src/check/normal.rs b/crates/moonbuild/src/check/normal.rs
index e10ebc3f8..7e4f0006d 100644
--- a/crates/moonbuild/src/check/normal.rs
+++ b/crates/moonbuild/src/check/normal.rs
@@ -18,7 +18,7 @@
 
 use anyhow::Context;
 
-use moonutil::common::{MoonbuildOpt, MooncOpt};
+use moonutil::common::{FileLock, MoonbuildOpt, MooncOpt};
 use moonutil::module::{convert_mdb_to_json, ModuleDB, ModuleDBJSON};
 use n2::load::State;
 use std::io::BufWriter;
@@ -43,6 +43,8 @@ pub fn write_pkg_lst(module: &ModuleDB, target_dir: &Path) -> anyhow::Result<()>
 
     let mj = convert_mdb_to_json(module);
     let pkg_json = target_dir.join("packages.json");
+    // packages.json now placed in target/, should be protected for mutil-thread write
+    let _lock = FileLock::lock(target_dir)?;
 
     // if the file exist and the old content is the same as the new content in `module`, don't rewrite it
     // otherwise we create and write
diff --git a/crates/moonutil/src/common.rs b/crates/moonutil/src/common.rs
index 689d3a936..f1e4b7235 100644
--- a/crates/moonutil/src/common.rs
+++ b/crates/moonutil/src/common.rs
@@ -22,7 +22,7 @@ use crate::module::{MoonMod, MoonModJSON};
 use crate::package::{convert_pkg_json_to_package, MoonPkg, MoonPkgJSON, Package};
 use anyhow::{bail, Context};
 use clap::ValueEnum;
-use fs4::FileExt;
+use fs4::fs_std::FileExt;
 use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
 use std::collections::{HashMap, HashSet};