Index: uspace/lib/c/generic/private/futex.h
===================================================================
--- uspace/lib/c/generic/private/futex.h	(revision 508b0df1a393bdc2b6b8e8f8f45be1a5be4a868b)
+++ uspace/lib/c/generic/private/futex.h	(revision c53e8137d0d1c1adfead47ccfe6351383d8d6af2)
@@ -81,5 +81,5 @@
 
 #define futex_give_to(fut, owner) ((void)0)
-#define futex_assert_is_locked(fut) assert((atomic_signed_t) (fut)->val.count <= 0)
+#define futex_assert_is_locked(fut) assert(atomic_load_explicit(&(fut)->val, memory_order_relaxed) <= 0)
 #define futex_assert_is_not_locked(fut) ((void)0)