diff --git a/src/hb-buffer-private.hh b/src/hb-buffer-private.hh
index 67a2752..c1acffd 100644
--- a/src/hb-buffer-private.hh
+++ b/src/hb-buffer-private.hh
@@ -153,6 +153,7 @@
   HB_INTERNAL void guess_properties (void);
 
   HB_INTERNAL void swap_buffers (void);
+  HB_INTERNAL void remove_output (void);
   HB_INTERNAL void clear_output (void);
   HB_INTERNAL void clear_positions (void);