diff --git a/mm/memory.c b/mm/memory.c
index 7a61a11..1a435b8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -45,6 +45,7 @@
 #include <linux/swap.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/ksm.h>
 #include <linux/rmap.h>
 #include <linux/module.h>
 #include <linux/delayacct.h>
@@ -1974,7 +1975,7 @@
 	 * Take out anonymous pages first, anonymous shared vmas are
 	 * not dirty accountable.
 	 */
-	if (PageAnon(old_page)) {
+	if (PageAnon(old_page) && !PageKsm(old_page)) {
 		if (!trylock_page(old_page)) {
 			page_cache_get(old_page);
 			pte_unmap_unlock(page_table, ptl);