diff --git a/coffee/lib/create-pipes.coffee b/coffee/lib/create-pipes.coffee
index eba2872..7e23f6b 100644
--- a/coffee/lib/create-pipes.coffee
+++ b/coffee/lib/create-pipes.coffee
@@ -18,8 +18,7 @@ module.exports = ->
 
   until created
     try
-      dir = tmp_dir + '/sync-exec-' + Math.floor Math.random() * 1000000000
-      fs.mkdir dir
+      dir = fs.mkdtemp tmp_dir + '/sync-exec-'
       created = true
 
     timeout t_limit, 'Can not create sync-exec directory'
diff --git a/js/lib/create-pipes.js b/js/lib/create-pipes.js
index 341169d..55c91bc 100644
--- a/js/lib/create-pipes.js
+++ b/js/lib/create-pipes.js
@@ -19,8 +19,7 @@
     }
     while (!created) {
       try {
-        dir = tmp_dir + '/sync-exec-' + Math.floor(Math.random() * 1000000000);
-        fs.mkdir(dir);
+        dir = fs.mkdtemp(tmp_dir + '/sync-exec-');
         created = true;
       } catch (_error) {}
       timeout(t_limit, 'Can not create sync-exec directory');