diff --git a/mm/compaction.c b/mm/compaction.c
index cbac727..9febc8c 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1230,7 +1230,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn, unsigned long
 
 	/* Pageblock boundaries */
 	start_pfn = pageblock_start_pfn(pfn);
-	end_pfn = min(start_pfn + pageblock_nr_pages, zone_end_pfn(cc->zone));
+	end_pfn = min(pageblock_end_pfn(pfn), zone_end_pfn(cc->zone)) - 1;
 
 	/* Scan before */
 	if (start_pfn != pfn) {
@@ -1241,7 +1241,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn, unsigned long
 
 	/* Scan after */
 	start_pfn = pfn + nr_isolated;
-	if (start_pfn != end_pfn)
+	if (start_pfn < end_pfn)
 		isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false);
 
 	/* Skip this pageblock in the future as it's full or nearly full */