diff --git a/akka-actor/src/main/scala/akka/dispatch/ThreadPoolBuilder.scala b/akka-actor/src/main/scala/akka/dispatch/ThreadPoolBuilder.scala
index aba58df3a4..3a5733f9ef 100644
--- a/akka-actor/src/main/scala/akka/dispatch/ThreadPoolBuilder.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/ThreadPoolBuilder.scala
@@ -212,6 +212,11 @@ trait ExecutorServiceDelegate extends ExecutorService {
   def invokeAny[T](callables: Collection[_ <: Callable[T]], l: Long, timeUnit: TimeUnit) = executor.invokeAny(callables, l, timeUnit)
 }
 
+/**
+ * The RejectedExecutionHandler used by Akka, it improves on CallerRunsPolicy
+ * by throwing a RejectedExecutionException if the executor isShutdown.
+ * (CallerRunsPolicy silently discards the runnable in this case, which is arguably broken)
+ */
 class SaneRejectedExecutionHandler extends RejectedExecutionHandler {
   def rejectedExecution(runnable: Runnable, threadPoolExecutor: ThreadPoolExecutor): Unit = {
     if (threadPoolExecutor.isShutdown) throw new RejectedExecutionException("Shutdown")