diff --git a/lib/modules/Thread.pmod b/lib/modules/Thread.pmod
index 7e5f13b69ff0ea608d3ee8f81c10c4bd9efc52e2..6a81929ee77567763cd63da3cc000ea5dd61decb 100644
--- a/lib/modules/Thread.pmod
+++ b/lib/modules/Thread.pmod
@@ -1,3 +1,5 @@
+#if constant(thread_create)
+
 constant Mutex=__builtin.mutex;
 constant Condition=__builtin.condition;
 
@@ -372,4 +374,4 @@ class Farm
   }
 }
 
-
+#endif /* constant(thread_create) */