--- Coro/Coro/State.xs	2012/04/13 10:53:25	1.420
+++ Coro/Coro/State.xs	2012/05/27 16:36:05	1.421
@@ -1506,7 +1506,7 @@
 #if HAVE_MMAP
   cctx->ssize = ((cctx_stacksize * sizeof (long) + PAGESIZE - 1) / PAGESIZE + CORO_STACKGUARD) * PAGESIZE;
   /* mmap supposedly does allocate-on-write for us */
-  cctx->sptr = mmap (0, cctx->ssize, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS, 0, 0);
+  cctx->sptr = mmap (0, cctx->ssize, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_ANONYMOUS, -1, 0);
 
   if (cctx->sptr != (void *)-1)
     {