diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index 06b6fdab639f..e657c45d91d2 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -27,6 +27,7 @@
 #include <linux/cache.h>
 #include <linux/profile.h>
 #include <linux/bitops.h>
+#include <linux/cpu.h>
 
 #include <asm/hwrpb.h>
 #include <asm/ptrace.h>