diff --git a/mm/ksm.c b/mm/ksm.c
index 4786b41..35b8aef 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -532,8 +532,8 @@
 	void *expected_mapping;
 	unsigned long kpfn;
 
-	expected_mapping = (void *)stable_node +
-				(PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
+	expected_mapping = (void *)((unsigned long)stable_node |
+					PAGE_MAPPING_KSM);
 again:
 	kpfn = READ_ONCE(stable_node->kpfn);
 	page = pfn_to_page(kpfn);