diff --git a/libs/temporal/superclock.cc b/libs/temporal/superclock.cc
index 8f3e398132..e8ec422b04 100644
--- a/libs/temporal/superclock.cc
+++ b/libs/temporal/superclock.cc
@@ -20,8 +20,7 @@
 
 int Temporal::most_recent_engine_sample_rate = 48000; /* have to pick something as a default */
 
-Temporal::superclock_t Temporal::_superclock_ticks_per_second = 0;
-
+Temporal::superclock_t Temporal::_superclock_ticks_per_second = 0; // zero to detect "early" usage
 void
 Temporal::set_sample_rate (int sr)
 {