diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ace64e5..a60995a 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -35,6 +35,7 @@
 
 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr);
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
 			      int write);
 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,