diff --git a/src/thread.cc b/src/thread.cc
index 24697ce..04c5105 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -220,7 +220,7 @@
   // Tell the kernel to stop using it.
   ss.ss_sp = NULL;
   ss.ss_flags = SS_DISABLE;
-  ss.ss_size = 0;
+  ss.ss_size = SIGSTKSZ; // Avoid ENOMEM failure with Mac OS' buggy libc.
   SigAltStack(&ss, NULL);
 
   // Free it.