diff --git a/mm/internal.h b/mm/internal.h
index 50807e1..858ad01 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -13,6 +13,9 @@
 
 #include <linux/mm.h>
 
+void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
+		unsigned long floor, unsigned long ceiling);
+
 static inline void set_page_count(struct page *page, int v)
 {
 	atomic_set(&page->_count, v);