diff --git a/crates/clap-host/src/scan.rs b/crates/clap-host/src/scan.rs
index 6bfbadd6..9edec8f5 100644
--- a/crates/clap-host/src/scan.rs
+++ b/crates/clap-host/src/scan.rs
@@ -150,7 +150,9 @@ mod tests {
     fn tmp(name: &str) -> PathBuf {
         let d = std::env::temp_dir().join(format!("soundcraft-clap-scan-{name}-{}", std::process::id()));
         let _ = std::fs::remove_dir_all(&d);
-        std::fs::create_dir_all(&d).unwrap();
+        // Created exclusively: a folder still there after the cleanup (someone else's) would
+        // let a link inside it redirect the test's writes.
+        std::fs::create_dir(&d).unwrap();
         d
     }
 
diff --git a/xtask/src/version.rs b/xtask/src/version.rs
index d469c2e9..510b060f 100644
--- a/xtask/src/version.rs
+++ b/xtask/src/version.rs
@@ -197,8 +197,11 @@ mod tests {
 
     #[test]
     fn a_failed_update_restores_the_manifest() {
-        let root = std::env::temp_dir().join(format!("xtask-version-restore-{}", std::process::id()));
-        std::fs::create_dir_all(&root).unwrap();
+        // Created exclusively: a folder already there (planted, or left by a failed run) would be
+        // someone else's, and a link inside it could redirect the writes below.
+        let nanos = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map_or(0, |d| d.subsec_nanos());
+        let root = std::env::temp_dir().join(format!("xtask-version-restore-{}-{nanos}", std::process::id()));
+        std::fs::create_dir(&root).unwrap();
         let path = root.join("Cargo.toml");
         std::fs::write(&path, MANIFEST).unwrap();
         let err = set(&root, &path, MANIFEST, "2.0.0", || Err("cargo update failed".into())).unwrap_err();