diff --git a/src/hb-font.cc b/src/hb-font.cc
index 1c63b0344..4e2adbb78 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -1894,6 +1894,7 @@ _hb_font_adopt_var_coords (hb_font_t *font,
   font->num_coords = coords_length;
 
   font->changed ();
+  font->serial_coords = font->serial;
 }
 
 /**