diff --git a/mm/ksm.c b/mm/ksm.c
index 80c29b1b2b8a..ca6d2a06a615 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1013,6 +1013,12 @@ static int try_to_merge_one_page(struct vm_area_struct *vma,
 			 */
 			set_page_stable_node(page, NULL);
 			mark_page_accessed(page);
+			/*
+			 * Page reclaim just frees a clean page with no dirty
+			 * ptes: make sure that the ksm page would be swapped.
+			 */
+			if (!PageDirty(page))
+				SetPageDirty(page);
 			err = 0;
 		} else if (pages_identical(page, kpage))
 			err = replace_page(vma, page, kpage, orig_pte);