diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0f7a6bd..5167d59 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Removed
+
+- manipulation SetSystemSignalActivation for activation states
+
 ## [4.6.0] - 2025-10-30
 
 - manipulation CreateNewContextStateWithAssociation for contexts
diff --git a/src/t2iapi/activation_state/activation_state_requests.proto b/src/t2iapi/activation_state/activation_state_requests.proto
index 60e4961..ef19b9e 100644
--- a/src/t2iapi/activation_state/activation_state_requests.proto
+++ b/src/t2iapi/activation_state/activation_state_requests.proto
@@ -1,6 +1,6 @@
 /*
 This Source Code Form is subject to the terms of the MIT License.
-Copyright (c) 2022 Draegerwerk AG & Co. KGaA.
+Copyright (c) 2022, 2026 Draegerwerk AG & Co. KGaA.
 
 SPDX-License-Identifier: MIT
 */
@@ -57,14 +57,4 @@ message ComponentActivationTransitionRequest {
                         // in the corresponding state element
     ComponentActivation start_activation = 2;  // the start @ActivationState value
     ComponentActivation end_activation = 3;  // the end @ActivationState value
-}
-
-/*
-Request to set the SystemSignalActivation with the given AlertSignalManifestation and AlertActivation for the alert
-system with the given handle.
- */
-message SetSystemSignalActivationRequest {
-    string handle = 1; // handle reference of the alert system
-    AlertSignalManifestation manifestation = 2;
-    AlertActivation activation = 3;
 }
\ No newline at end of file
diff --git a/src/t2iapi/activation_state/service.proto b/src/t2iapi/activation_state/service.proto
index b681099..ffe1e9c 100644
--- a/src/t2iapi/activation_state/service.proto
+++ b/src/t2iapi/activation_state/service.proto
@@ -1,6 +1,6 @@
 /*
 This Source Code Form is subject to the terms of the MIT License.
-Copyright (c) 2022 Draegerwerk AG & Co. KGaA.
+Copyright (c) 2022, 2026 Draegerwerk AG & Co. KGaA.
 
 SPDX-License-Identifier: MIT
 */
@@ -56,10 +56,4 @@ service ActivationStateService {
   t2iapi.activation_state.SetAlertConditionAndAlertSignalActivationStateRequest)
       returns (BasicResponse);
 
-  /*
-  Set a SystemSignalActivation for a alert system with the given handle.
-   */
-  rpc SetSystemSignalActivation (t2iapi.activation_state.SetSystemSignalActivationRequest)
-      returns (BasicResponse);
 }
-