diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index 6fa682eef7a0..721b2365dbca 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -357,7 +357,8 @@ static bool migrate_vma_check_page(struct page *page, struct page *fault_page)
 }
 
 /*
- * Unmaps pages for migration. Returns number of unmapped pages.
+ * Unmaps pages for migration. Returns number of source pfns marked as
+ * migrating.
  */
 static unsigned long migrate_device_unmap(unsigned long *src_pfns,
 					  unsigned long npages,
@@ -373,8 +374,11 @@ static unsigned long migrate_device_unmap(unsigned long *src_pfns,
 		struct page *page = migrate_pfn_to_page(src_pfns[i]);
 		struct folio *folio;
 
-		if (!page)
+		if (!page) {
+			if (src_pfns[i] & MIGRATE_PFN_MIGRATE)
+				unmapped++;
 			continue;
+		}
 
 		/* ZONE_DEVICE pages are not on LRU */
 		if (!is_zone_device_page(page)) {