diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 2100a8f7bd86..4008e2ce73c1 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -110,6 +110,7 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/smp_lock.h>
 
 #include <asm/system.h>