diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index a118f3c..4aab6f1 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -93,6 +93,7 @@
 void put_files_struct(struct files_struct *fs);
 void reset_files_struct(struct files_struct *);
 int unshare_files(struct files_struct **);
+struct files_struct *dup_fd(struct files_struct *, int *);
 
 extern struct kmem_cache *files_cachep;