diff --git a/mm/mm_init.c b/mm/mm_init.c
index 4c17a892924d..01ced0553ce9 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1142,6 +1142,8 @@ void __ref memmap_init_zone_device(struct zone *zone,
 	if (!nr_pages)
 		return;
 
+	VM_WARN_ON(!IS_ALIGNED(start_pfn | nr_pages, pfns_per_compound));
+
 	/*
 	 * Seed the reusable head-page template from the first real struct
 	 * page. The normal page-init and refcount helpers must operate on