diff --git a/arch/x86/mm/pat_rbtree.c b/arch/x86/mm/pat_rbtree.c
index 9063f40b638bd..07de4cb8cc30d 100644
--- a/arch/x86/mm/pat_rbtree.c
+++ b/arch/x86/mm/pat_rbtree.c
@@ -223,7 +223,9 @@ int rbt_memtype_check_insert(struct memtype *new, unsigned long *ret_type)
 						new->type, ret_type);
 
 	if (!err) {
-		new->type = *ret_type;
+		if (ret_type)
+			new->type = *ret_type;
+
 		memtype_rb_insert(&memtype_rbroot, new);
 	}
 	return err;