diff --git a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level.h b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level.h
index 528cc0478f..220d131829 100644
--- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level.h
+++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/pgtable-3level.h
@@ -119,13 +119,7 @@ static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *pt
 	ptep->pte_high = 0;
 }
 
-static inline void pmd_clear(pmd_t *pmd)
-{
-	u32 *tmp = (u32 *)pmd;
-	*tmp = 0;
-	smp_wmb();
-	*(tmp + 1) = 0;
-}
+#define pmd_clear(xp)	do { set_pmd(xp, __pmd(0)); } while (0)
 
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {