diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 1ac28c6..35ba254 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -39,6 +39,7 @@
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
+#include <linux/slab.h>
 #include <asm/io.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>