diff --git a/src/hb-mutex.hh b/src/hb-mutex.hh
index 35f1fded1..a760e7317 100644
--- a/src/hb-mutex.hh
+++ b/src/hb-mutex.hh
@@ -127,8 +127,6 @@ typedef int hb_mutex_impl_t;
 
 struct hb_mutex_t
 {
-  /* TODO Add tracing. */
-
   hb_mutex_impl_t m;
 
   void init   () { hb_mutex_impl_init   (&m); }