diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index aebf482..d89dce3 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -62,6 +62,12 @@
   hb_var_int_t   var;
 } hb_glyph_position_t;
 
+typedef enum {
+  HB_BUFFER_CONTENT_TYPE_INVALID = 0,
+  HB_BUFFER_CONTENT_TYPE_UNICODE,
+  HB_BUFFER_CONTENT_TYPE_GLYPHS
+} hb_buffer_content_type_t;
+
 
 hb_buffer_t *
 hb_buffer_create (void);
@@ -88,6 +94,14 @@
 
 
 void
+hb_buffer_set_content_type (hb_buffer_t              *buffer,
+			    hb_buffer_content_type_t  content_type);
+
+hb_buffer_content_type_t
+hb_buffer_get_content_type (hb_buffer_t *buffer);
+
+
+void
 hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
 			     hb_unicode_funcs_t *unicode_funcs);