--- include/vki/vki-openbsd.h.orig
+++ include/vki/vki-openbsd.h
@@ -1544,9 +1544,9 @@
 #define VKI_MAP_PRIVATE	0x02		/* Changes are private */
 #define VKI_MAP_FIXED	0x10		/* Interpret addr exactly */
 #define VKI_MAP_NORESERVE	0x0040		/* don't check for reservations */
-#define	VKI_MAP_STACK	0x400
 #define VKI_MAP_ANON	0x1000	/* don't use a file */
 #define	VKI_MAP_ANONYMOUS	VKI_MAP_ANON
+#define	VKI_MAP_STACK	0x4000

 //----------------------------------------------------------------------
 // From sys/stat.h
