--- a/python/mach/mach/main.py
+++ b/python/mach/mach/main.py
@@ -255,17 +255,17 @@ To see more help for a specific command,
         """
         if module_name is None:
             # Ensure parent module is present otherwise we'll (likely) get
             # an error due to unknown parent.
             if b'mach.commands' not in sys.modules:
                 mod = imp.new_module(b'mach.commands')
                 sys.modules[b'mach.commands'] = mod
 
-            module_name = 'mach.commands.%s' % uuid.uuid1().get_hex()
+            module_name = 'mach.commands.%s' % uuid.uuid4().get_hex()
 
         try:
             imp.load_source(module_name, path)
         except IOError as e:
             if e.errno != errno.ENOENT:
                 raise
 
             raise MissingFileError('%s does not exist' % path)