diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6bf1f1a..cbcbfde 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1247,6 +1247,11 @@
 	def_bool X86_64
 	depends on MEMORY_HOTPLUG
 
+config ILLEGAL_POINTER_VALUE
+       hex
+       default 0 if X86_32
+       default 0xdead000000000000 if X86_64
+
 source "mm/Kconfig"
 
 config HIGHPTE