diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 5199db2..512ec6b 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -781,6 +781,18 @@
        memcpy(dst, src, count * sizeof(pgd_t));
 }
 
+/*
+ * The x86 doesn't have any external MMU info: the kernel page
+ * tables contain all the necessary information.
+ */
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
+{
+}
+static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
+		unsigned long addr, pmd_t *pmd)
+{
+}
 
 #include <asm-generic/pgtable.h>
 #endif	/* __ASSEMBLY__ */