diff --git a/src/hb-ot-kern-table.hh b/src/hb-ot-kern-table.hh
index 63551d313cdb148cf0e3c151eba9c64d4505bc4c..891f3eab9d5703ec00657924080de465564bacdc 100644
--- a/src/hb-ot-kern-table.hh
+++ b/src/hb-ot-kern-table.hh
@@ -483,7 +483,12 @@ struct kern
 
       hb_kern_machine_t<accelerator_t> machine (*this);
 
+      if (!buffer->message (font, "start kern table"))
+        return;
+
       machine.kern (font, buffer, kern_mask);
+
+      (void) buffer->message (font, "end kern table");
     }
 
     private: