diff --git a/arch/m32r/kernel/smpboot.c b/arch/m32r/kernel/smpboot.c
index 3eb3059..9dae410 100644
--- a/arch/m32r/kernel/smpboot.c
+++ b/arch/m32r/kernel/smpboot.c
@@ -43,6 +43,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/err.h>
 #include <linux/irq.h>
 #include <linux/bootmem.h>
 #include <linux/delay.h>