diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index e6288b4..78ff6d2 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -163,7 +163,7 @@
   if (ot_face->glyf->get_extents (glyph, &extents))
   {
     const OT::vmtx_accelerator_t &vmtx = *ot_face->vmtx;
-    hb_position_t tsb = vmtx.get_side_bearing (glyph);
+    hb_position_t tsb = vmtx.get_side_bearing (font, glyph);
     *y = font->em_scale_y (extents.y_bearing + tsb);
     return true;
   }