diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 7e33f2c..438951d 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -16,6 +16,7 @@
 #include <linux/err.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 
 /*
  * This function can't run concurrently against mmu_notifier_register