diff --git a/actor/src/main/scala/org/apache/pekko/dispatch/AbstractDispatcher.scala b/actor/src/main/scala/org/apache/pekko/dispatch/AbstractDispatcher.scala
index e77cbbcc4e..f2d6aa8d56 100644
--- a/actor/src/main/scala/org/apache/pekko/dispatch/AbstractDispatcher.scala
+++ b/actor/src/main/scala/org/apache/pekko/dispatch/AbstractDispatcher.scala
@@ -34,7 +34,7 @@ import com.typesafe.config.Config
 
 final case class Envelope private (message: Any, sender: ActorRef) {
 
-  @noinline
+  @noinline // not inlined to permit downstream bytecode instrumentation to attach context information to the Envelope
   def copy(message: Any = message, sender: ActorRef = sender) = {
     Envelope(message, sender)
   }
diff --git a/actor/src/main/scala/org/apache/pekko/dispatch/ThreadPoolBuilder.scala b/actor/src/main/scala/org/apache/pekko/dispatch/ThreadPoolBuilder.scala
index 91fc7b98df..205c2e4ac7 100644
--- a/actor/src/main/scala/org/apache/pekko/dispatch/ThreadPoolBuilder.scala
+++ b/actor/src/main/scala/org/apache/pekko/dispatch/ThreadPoolBuilder.scala
@@ -85,6 +85,8 @@ final case class ThreadPoolConfig(
     queueFactory: ThreadPoolConfig.QueueFactory = ThreadPoolConfig.linkedBlockingQueue(),
     rejectionPolicy: RejectedExecutionHandler = ThreadPoolConfig.defaultRejectionPolicy)
     extends ExecutorServiceFactoryProvider {
+  // Written explicitly to permit non-inlined defn; this is necessary for downstream instrumentation that stores extra
+  // context information on the config
   @noinline
   def copy(
       allowCorePoolTimeout: Boolean = allowCorePoolTimeout,
diff --git a/actor/src/main/scala/org/apache/pekko/util/MessageBuffer.scala b/actor/src/main/scala/org/apache/pekko/util/MessageBuffer.scala
index 3e538cc1b4..3b61ac637c 100644
--- a/actor/src/main/scala/org/apache/pekko/util/MessageBuffer.scala
+++ b/actor/src/main/scala/org/apache/pekko/util/MessageBuffer.scala
@@ -160,7 +160,7 @@ final class MessageBuffer private (private var _head: MessageBuffer.Node, privat
 
 object MessageBuffer {
   private final class Node(var next: Node, val message: Any, val ref: ActorRef) {
-    @noinline
+    @noinline // not inlined to permit downstream bytecode instrumentation to apply context information on the Node to the message
     def apply(f: (Any, ActorRef) => Unit): Unit = {
       f(message, ref)
     }