diff --git a/mm/vmstat.c b/mm/vmstat.c
index fadf791..c64d169 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/mm.h>
+#include <linux/err.h>
 #include <linux/module.h>
 #include <linux/cpu.h>
 #include <linux/sched.h>