diff --git a/src/hb-font.cc b/src/hb-font.cc
index d549455ea..9800ea7dd 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -729,7 +729,7 @@ hb_face_set_index (hb_face_t    *face,
   if (hb_object_is_inert (face))
     return;
 
-  face->index = 0;
+  face->index = index;
 }
 
 unsigned int