diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4446a523e684..afcaa657a022 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -807,7 +807,7 @@ static inline void __free_one_page(struct page *page,
 	struct page *buddy;
 	unsigned int max_order;
 
-	max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
+	max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order);
 
 	VM_BUG_ON(!zone_is_initialized(zone));
 	VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
@@ -820,7 +820,7 @@ static inline void __free_one_page(struct page *page,
 	VM_BUG_ON_PAGE(bad_range(zone, page), page);
 
 continue_merging:
-	while (order < max_order - 1) {
+	while (order < max_order) {
 		buddy_pfn = __find_buddy_pfn(pfn, order);
 		buddy = page + (buddy_pfn - pfn);
 
@@ -844,7 +844,7 @@ continue_merging:
 		pfn = combined_pfn;
 		order++;
 	}
-	if (max_order < MAX_ORDER) {
+	if (order < MAX_ORDER - 1) {
 		/* If we are here, it means order is >= pageblock_order.
 		 * We want to prevent merge between freepages on isolate
 		 * pageblock and normal pageblock. Without this, pageblock
@@ -865,7 +865,7 @@ continue_merging:
 						is_migrate_isolate(buddy_mt)))
 				goto done_merging;
 		}
-		max_order++;
+		max_order = order + 1;
 		goto continue_merging;
 	}