diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index ce6ad7e6a7d7..33f71b01fd22 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -79,6 +79,7 @@ else
         UTS_MACHINE := x86_64
         CHECKFLAGS += -D__x86_64__ -m64
 
+        biarch := -m64
         KBUILD_AFLAGS += -m64
         KBUILD_CFLAGS += -m64