diff --git a/mm/Makefile b/mm/Makefile
index 98c4eae..b424d5e 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -78,3 +78,4 @@
 obj-$(CONFIG_MEMORY_BALLOON) += balloon_compaction.o
 obj-$(CONFIG_PAGE_EXTENSION) += page_ext.o
 obj-$(CONFIG_CMA_DEBUGFS) += cma_debug.o
+obj-$(CONFIG_USERFAULTFD) += userfaultfd.o