diff --git a/include/hsmcpp/hsm.hpp b/include/hsmcpp/hsm.hpp
index d12d771..9a2d7b3 100644
--- a/include/hsmcpp/hsm.hpp
+++ b/include/hsmcpp/hsm.hpp
@@ -437,6 +437,15 @@ class HierarchicalStateMachine {
      */
     bool isStateActive(const StateID_t state) const;
 
+    /**
+     * @brief Called whenever a change state occurs.
+     * @details Overwrite this function to get informed when a new state is activated.
+     *
+     * @param state ID of the new state
+     *
+     */
+    virtual void onStateChanged(const StateID_t state) const { }
+
     /**
      * @brief Trigger a transition in the HSM.
      * @details This function sends event to HSM to trigger a potential transition. The transition is executed asynchronously,
diff --git a/src/HsmImpl.cpp b/src/HsmImpl.cpp
index b00c921..93ca06f 100644
--- a/src/HsmImpl.cpp
+++ b/src/HsmImpl.cpp
@@ -720,6 +720,8 @@ void HierarchicalStateMachine::Impl::onStateChanged(const StateID_t state, const
     } else {
         HSM_TRACE_WARNING("no callback registered for state <%s>", getStateName(state).c_str());
     }
+	// notify parent
+	if (mParent) mParent->onStateChanged(state);
 }
 
 void HierarchicalStateMachine::Impl::executeStateAction(const StateID_t state, const StateActionTrigger actionTrigger) {