diff --git a/gc.c b/gc.c
index 70502e01f5..df8e22fb0f 100644
--- a/gc.c
+++ b/gc.c
@@ -1322,7 +1322,7 @@ Init_stack(addr)
     /* ruby crashes on IA64 if compiled with optimizer on */
     /* when if STACK_LEVEL_MAX is greater than this magic number */
     /* I know this is a kludge.  I suspect optimizer bug */
-#define IA64_MAGIC_STACK_LIMIT 65535
+#define IA64_MAGIC_STACK_LIMIT 32768
     if (STACK_LEVEL_MAX > IA64_MAGIC_STACK_LIMIT)
 	STACK_LEVEL_MAX = IA64_MAGIC_STACK_LIMIT;
 #endif