diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4fb3c5fa19..97e75c5733 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -104,9 +104,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed FixedFeedModelSpec [#861](https://github.com/ie3-institute/simona/issues/861)
 - Fixing duration calculation in result events [#801](https://github.com/ie3-institute/simona/issues/801)
 - Handle MobSim requests for current prices [#892](https://github.com/ie3-institute/simona/issues/892)
-- Fix activation of Hp when not under control of an EM [#922](https://github.com/ie3-institute/simona/issues/922)
 - Fixed ThermalStorageResults having multiple entries [#924](https://github.com/ie3-institute/simona/issues/924)
 - Fix determineState of ThermalHouse [#926](https://github.com/ie3-institute/simona/issues/926)
+- Fix activation of Hp when not under control of an EM [#922](https://github.com/ie3-institute/simona/issues/922)
 - Refactoring of `ThermalGrid.handleInfeed` to fix thermal storage recharge correctly when empty [#930](https://github.com/ie3-institute/simona/issues/930)
 
 ## [3.0.0] - 2023-08-07
diff --git a/src/main/scala/edu/ie3/simona/agent/participant/hp/HpAgentFundamentals.scala b/src/main/scala/edu/ie3/simona/agent/participant/hp/HpAgentFundamentals.scala
index 90e3ec0895..121004738f 100644
--- a/src/main/scala/edu/ie3/simona/agent/participant/hp/HpAgentFundamentals.scala
+++ b/src/main/scala/edu/ie3/simona/agent/participant/hp/HpAgentFundamentals.scala
@@ -272,7 +272,7 @@ trait HpAgentFundamentals
           baseStateData.copy(
             stateDataStore = updatedStateDataStore,
             additionalActivationTicks =
-              baseStateData.additionalActivationTicks + nextThreshold.tick,
+              baseStateData.additionalActivationTicks ++ Set(nextThreshold.tick),
           )
         case _ =>
           baseStateData.copy(