diff --git a/pango/pangofc-shape.c b/pango/pangofc-shape.c
index 51404f0..6279b65 100644
--- a/pango/pangofc-shape.c
+++ b/pango/pangofc-shape.c
@@ -342,6 +342,7 @@ _pango_fc_shape (PangoFont           *font,
   hb_buffer_set_direction (hb_buffer, hb_direction);
   hb_buffer_set_script (hb_buffer, hb_glib_script_to_script (analysis->script));
   hb_buffer_set_language (hb_buffer, hb_language_from_string (pango_language_to_string (analysis->language), -1));
+  hb_buffer_set_cluster_level (hb_buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
   hb_buffer_set_flags (hb_buffer,
 		       (item_offset == 0 ? HB_BUFFER_FLAG_BOT : 0) |
 		       (item_offset + item_length == paragraph_length ? HB_BUFFER_FLAG_EOT : 0));
