--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -176,13 +176,11 @@
         # FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
         cflags-$(CONFIG_MK8)		+= -march=k8
         cflags-$(CONFIG_MPSC)		+= -march=nocona
-        ifeq ($(CONFIG_X86_64_VERSION),1)
+        CONFIG_X86_64_VERSION	=	1
           cflags-$(CONFIG_GENERIC_CPU)		+= -mtune=generic
           rustflags-$(CONFIG_GENERIC_CPU)	+= -Ztune-cpu=generic
-        else
           cflags-$(CONFIG_GENERIC_CPU)		+= -march=x86-64
           rustflags-$(CONFIG_GENERIC_CPU)	+= -Ctarget-cpu=x86-64-v$(CONFIG_X86_64_VERSION)
-        endif
         cflags-$(CONFIG_MK8SSE3)	+= -march=k8-sse3
         cflags-$(CONFIG_MK10) 		+= -march=amdfam10
         cflags-$(CONFIG_MBARCELONA) 	+= -march=barcelona
