diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 7219560..571130e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -205,7 +205,7 @@
 	zone_span_writelock(zone);
 
 	old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
-	if (start_pfn < zone->zone_start_pfn)
+	if (!zone->spanned_pages || start_pfn < zone->zone_start_pfn)
 		zone->zone_start_pfn = start_pfn;
 
 	zone->spanned_pages = max(old_zone_end_pfn, end_pfn) -
@@ -220,7 +220,7 @@
 	unsigned long old_pgdat_end_pfn =
 		pgdat->node_start_pfn + pgdat->node_spanned_pages;
 
-	if (start_pfn < pgdat->node_start_pfn)
+	if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn)
 		pgdat->node_start_pfn = start_pfn;
 
 	pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) -