diff --git a/arch/ppc/kernel/idle.c b/arch/ppc/kernel/idle.c
index fba29c876b62ab843d06e308ef2590c9f3999f85..0a12fbef73470d8df2c712de0e55137b91a86f88 100644
--- a/arch/ppc/kernel/idle.c
+++ b/arch/ppc/kernel/idle.c
@@ -32,6 +32,7 @@
 #include <asm/cache.h>
 #include <asm/cputable.h>
 #include <asm/machdep.h>
+#include <asm/smp.h>
 
 void default_idle(void)
 {