diff --git a/arch/efi/Makefile b/arch/efi/Makefile
index 85cb65561..b078bd0e3 100644
--- a/arch/efi/Makefile
+++ b/arch/efi/Makefile
@@ -1,3 +1,5 @@
+KBUILD_DEFCONFIG := efi_defconfig
+
 CFLAGS += -fpic -fshort-wchar -mno-sse -mno-mmx
 
 ifeq ($(CONFIG_X86_32),y)
diff --git a/arch/sandbox/Makefile b/arch/sandbox/Makefile
index ed5d3a3da..e3fb03955 100644
--- a/arch/sandbox/Makefile
+++ b/arch/sandbox/Makefile
@@ -1,3 +1,4 @@
+KBUILD_DEFCONFIG := sandbox_defconfig
 
 CPPFLAGS += -D__SANDBOX__ -fno-strict-aliasing
 
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index a78fa22ac..da17d70bd 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -1,3 +1,5 @@
+KBUILD_DEFCONFIG := generic_defconfig
+
 CPPFLAGS += -D__X86__ -fno-strict-aliasing
 
 board-y := x86_generic