diff --git a/mm/ksm.c b/mm/ksm.c
index 43bc893470b40512e26bdd129fb2194708bfbbdc..b5b907cb0f900c3b5e24dceef352ca48155d1a4a 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -800,6 +800,8 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
 
 	page_remove_rmap(page);
+	if (!page_mapped(page))
+		try_to_free_swap(page);
 	put_page(page);
 
 	pte_unmap_unlock(ptep, ptl);