diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 106039d..3016ccb 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -147,6 +147,7 @@
 	$(Q)$(MAKE) $(clean)=$(boot)
 	$(Q)$(MAKE) $(clean)=$(boot)/dts
 
+ifeq ($(KBUILD_EXTMOD),)
 # We need to generate vdso-offsets.h before compiling certain files in kernel/.
 # In order to do that, we should use the archprepare target, but we can't since
 # asm-offsets.h is included in some files used to generate vdso-offsets.h, and
@@ -156,6 +157,7 @@
 prepare: vdso_prepare
 vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h
+endif
 
 define archhelp
   echo  '* Image.gz      - Compressed kernel image (arch/$(ARCH)/boot/Image.gz)'