Index: src/threading.m
==================================================================
--- src/threading.m
+++ src/threading.m
@@ -31,11 +31,11 @@
 of_once(of_once_t *control, void (*func)(void))
 {
 	if (of_atomic_int_cmpswap(control, 0, 1)) {
 		func();
 
-		of_memory_barrier();
+		of_memory_barrier_sync();
 
 		of_atomic_int_inc(control);
 	} else
 		while (*control == 1)
 			of_thread_yield();