diff --git a/src/worker-entry.ts b/src/worker-entry.ts
index 4056ade..58386ea 100644
--- a/src/worker-entry.ts
+++ b/src/worker-entry.ts
@@ -322,8 +322,10 @@ if (parentPort !== null && handshake?.runtimeId !== undefined) {
   await initRuntimeWorker(handshake, attachEndpointHandler);
 }
 
-// parentPort is null when this module evaluates on the MAIN thread — user
-// code importing peers.ts (e.g. a moroutine that dispatches to a peer) pulls
-// this module in transitively. There is no endpoint to attach there; the
-// handshake above is null on main too, so evaluation is inert by design.
+// Normally this module only evaluates as a worker's entry module, where
+// parentPort is set. Nothing in the library import graph pulls it in —
+// peers.ts and runtime-worker receive its handler by injection, not by
+// importing us — but an explicit import (e.g. from a test) can evaluate it
+// on the MAIN thread, where parentPort is null and there is no endpoint to
+// attach. The handshake above is null on main too, so evaluation is inert.
 if (parentPort !== null) attachEndpointHandler(parentPort);