diff --git a/clutter/clutter-main.c b/clutter/clutter-main.c
index 7d4d8159a..80d7bf88c 100644
--- a/clutter/clutter-main.c
+++ b/clutter/clutter-main.c
@@ -215,11 +215,13 @@ clutter_threads_init_default (void)
 {
   g_mutex_init (&clutter_threads_mutex);
 
+#ifndef HAVE_CLUTTER_WIN32
   if (clutter_threads_lock == NULL)
     clutter_threads_lock = clutter_threads_impl_lock;
 
   if (clutter_threads_unlock == NULL)
     clutter_threads_unlock = clutter_threads_impl_unlock;
+#endif
 }
 
 #define ENVIRONMENT_GROUP       "Environment"