diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 31555b689eb9..c4f568206544 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -215,7 +215,7 @@ int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
  * all pages in [start_pfn...end_pfn) must be in the same zone.
  * zone->lock must be held before call this.
  *
- * Returns 1 if all pages in the range are isolated.
+ * Returns the last tested pfn.
  */
 static unsigned long
 __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,