diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 326250996b4e..c8077e936691 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -19,6 +19,11 @@ struct migration_target_control;
  */
 #define MIGRATEPAGE_SUCCESS		0
 
+/*
+ * Keep sync with:
+ * - macro MIGRATE_REASON in include/trace/events/migrate.h
+ * - migrate_reason_names[MR_TYPES] in mm/debug.c
+ */
 enum migrate_reason {
 	MR_COMPACTION,
 	MR_MEMORY_FAILURE,
@@ -32,7 +37,6 @@ enum migrate_reason {
 	MR_TYPES
 };
 
-/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
 extern const char *migrate_reason_names[MR_TYPES];
 
 #ifdef CONFIG_MIGRATION
diff --git a/mm/debug.c b/mm/debug.c
index e61037cded98..fae0f81ad831 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -26,6 +26,7 @@ const char *migrate_reason_names[MR_TYPES] = {
 	"numa_misplaced",
 	"contig_range",
 	"longterm_pin",
+	"demotion",
 };
 
 const struct trace_print_flags pageflag_names[] = {