diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index d6094281aa53d00aef7420fa10a0ac10f7ec690a..3d7da911cc8c90cf0cf0d78382a7b6b8f36d0416 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -29,3 +29,5 @@ thunk.S-dir = lib
 module.c-dir = kernel
 
 CFLAGS_csum-partial.o := -Dcsum_partial=arch_csum_partial
+
+subdir- := util