diff --git a/packages/runtime_info/actor_stats.pony b/packages/runtime_info/actor_stats.pony
index b2068f0faa..28e9c64a12 100644
--- a/packages/runtime_info/actor_stats.pony
+++ b/packages/runtime_info/actor_stats.pony
@@ -2,7 +2,9 @@ use @pony_actor_stats[_ActorStats]()
 
 primitive ActorStats
   """
-  Provides functions that expose statistics about the current actor.
+  Provides functions that expose statistics about the current actor. All
+  methods will return '0' if the runtime used the program wasn't compiled with
+  runtime statistics turned on.
   """
 
   fun heap_mem_allocated(auth: ActorStatsAuth): USize =>
diff --git a/packages/runtime_info/scheduler_stats.pony b/packages/runtime_info/scheduler_stats.pony
index 1ed4f008c1..dab2aef176 100644
--- a/packages/runtime_info/scheduler_stats.pony
+++ b/packages/runtime_info/scheduler_stats.pony
@@ -2,7 +2,9 @@ use @pony_scheduler_stats[_SchedulerStats]()
 
 primitive SchedulerStats
   """
-  Provides functions that expose statistics about the current scheduler.
+  Provides functions that expose statistics about the current scheduler. All
+  methods will return '0' if the runtime used the program wasn't compiled with
+  runtime statistics turned on.
   """
 
   fun total_mem_allocated(auth: SchedulerStatsAuth): I64 =>