diff --git a/src/include/stdlib.h b/src/include/stdlib.h
index eb67d20..8bae40f 100644
--- a/src/include/stdlib.h
+++ b/src/include/stdlib.h
@@ -3,6 +3,8 @@
 
 #include <stddef.h>
 
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+
 extern void *malloc(size_t size);
 void free(void *ptr);
 
diff --git a/src/superio/smsc/smscsuperio/superio.c b/src/superio/smsc/smscsuperio/superio.c
index 0ae1818..20e5cf6 100644
--- a/src/superio/smsc/smscsuperio/superio.c
+++ b/src/superio/smsc/smscsuperio/superio.c
@@ -40,6 +40,7 @@
 #include <console/console.h>
 #include <uart8250.h>
 #include <pc80/keyboard.h>
+#include <stdlib.h>
 #include "chip.h"
 
 /* The following Super I/O chips are currently supported by this driver: */
@@ -66,9 +67,6 @@
 static uint8_t superio_id = 0;
 static uint8_t superio_rev = 0;
 
-/* TODO: Move somewhere else, but where? */
-#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
-
 /**
  * A list of all possible logical devices which may be supported by at least
  * one of the Super I/O chips. These values are used as index into the