diff --git a/mm/ksm.c b/mm/ksm.c
index 6cb60f46cce5..5b6be9eeb095 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1133,6 +1133,13 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	} else {
 		newpte = pte_mkspecial(pfn_pte(page_to_pfn(kpage),
 					       vma->vm_page_prot));
+		/*
+		 * We're replacing an anonymous page with a zero page, which is
+		 * not anonymous. We need to do proper accounting otherwise we
+		 * will get wrong values in /proc, and a BUG message in dmesg
+		 * when tearing down the mm.
+		 */
+		dec_mm_counter(mm, MM_ANONPAGES);
 	}
 
 	flush_cache_page(vma, addr, pte_pfn(*ptep));