diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6edcea7..abc8484 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -695,7 +695,7 @@
 #define ZONES_MASK		((1UL << ZONES_WIDTH) - 1)
 #define NODES_MASK		((1UL << NODES_WIDTH) - 1)
 #define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
-#define LAST_CPUPID_MASK	((1UL << LAST_CPUPID_WIDTH) - 1)
+#define LAST_CPUPID_MASK	((1UL << LAST_CPUPID_SHIFT) - 1)
 #define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
 
 static inline enum zone_type page_zonenum(const struct page *page)