diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index c1b9a3bb10..5812321cae 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3004,7 +3004,7 @@ static int _get_page_type(struct page_info *page, unsigned long type,
             if ( unlikely(!cpumask_empty(mask)) &&
                  /* Shadow mode: track only writable pages. */
                  (!shadow_mode_enabled(d) ||
-                  ((nx & PGT_type_mask) == PGT_writable_page)) )
+                  ((x & PGT_type_mask) == PGT_writable_page)) )
             {
                 perfc_incr(need_flush_tlb_flush);
                 /*