diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index adfe7dabf..1f765c78d 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -21,6 +21,8 @@
 
 - Power distribution results are no longer available through the `power_status` streams in the `*Pool`s.    They can now be accessed as a stream from a separate property `power_distribution_results`, which is available from all the `*Pool`s.
 
+- The `ConfigManagingActor` now uses `collections.abc.Mapping` as the output sender type. This change indicates that the broadcasted configuration is intended to be read-only.
+
 ## New Features
 
 - Classes `Bounds` and `SystemBounds` now implement the `__contains__` method, allowing the use of the `in` operator to check whether a value falls within the bounds or not.
diff --git a/src/frequenz/sdk/actor/_config_managing.py b/src/frequenz/sdk/actor/_config_managing.py
index bf7c72a4c..a141f0571 100644
--- a/src/frequenz/sdk/actor/_config_managing.py
+++ b/src/frequenz/sdk/actor/_config_managing.py
@@ -32,7 +32,7 @@ class ConfigManagingActor(Actor):
     def __init__(
         self,
         config_path: pathlib.Path | str,
-        output: Sender[dict[str, Any]],
+        output: Sender[abc.Mapping[str, Any]],
         event_types: abc.Set[EventType] = frozenset(EventType),
         *,
         name: str | None = None,
@@ -58,9 +58,9 @@ def __init__(
         self._file_watcher: FileWatcher = FileWatcher(
             paths=[self._config_path.parent], event_types=event_types
         )
-        self._output: Sender[dict[str, Any]] = output
+        self._output: Sender[abc.Mapping[str, Any]] = output
 
-    def _read_config(self) -> dict[str, Any]:
+    def _read_config(self) -> abc.Mapping[str, Any]:
         """Read the contents of the configuration file.
 
         Returns:
diff --git a/tests/actor/test_config_manager.py b/tests/actor/test_config_manager.py
index 88d15c139..c31417d6a 100644
--- a/tests/actor/test_config_manager.py
+++ b/tests/actor/test_config_manager.py
@@ -4,6 +4,7 @@
 """Test for ConfigManager."""
 import os
 import pathlib
+from collections.abc import Mapping
 from typing import Any
 
 import pytest
@@ -65,7 +66,7 @@ async def test_update(self, config_file: pathlib.Path) -> None:
         - the initial content of the content file is correct
         - the config file modifications are picked up and the new content is correct
         """
-        config_channel: Broadcast[dict[str, Any]] = Broadcast(
+        config_channel: Broadcast[Mapping[str, Any]] = Broadcast(
             name="Config Channel", resend_latest=True
         )
         config_receiver = config_channel.new_receiver()
@@ -91,7 +92,7 @@ async def test_update(self, config_file: pathlib.Path) -> None:
 
     async def test_update_relative_path(self, config_file: pathlib.Path) -> None:
         """Test ConfigManagingActor with a relative path."""
-        config_channel: Broadcast[dict[str, Any]] = Broadcast(
+        config_channel: Broadcast[Mapping[str, Any]] = Broadcast(
             name="Config Channel", resend_latest=True
         )
         config_receiver = config_channel.new_receiver()