diff --git a/src/gui/GuiRunner.cc b/src/gui/GuiRunner.cc
index c33548f138..b491c4c86b 100644
--- a/src/gui/GuiRunner.cc
+++ b/src/gui/GuiRunner.cc
@@ -266,13 +266,6 @@ void GuiRunner::RequestState()
   this->dataPtr->node.Request(this->dataPtr->stateTopic + "_async", req);
 }
 
-/////////////////////////////////////////////////
-void GuiRunner::OnPluginAdded(const QString &)
-{
-  // This function used to call Update on the plugin, but that's no longer
-  // necessary. The function is left here for ABI compatibility.
-}
-
 /////////////////////////////////////////////////
 void GuiRunner::OnStateAsyncService(const msgs::SerializedStepMap &_res)
 {
diff --git a/src/gui/GuiRunner.hh b/src/gui/GuiRunner.hh
index a3da1fda5b..277964a930 100644
--- a/src/gui/GuiRunner.hh
+++ b/src/gui/GuiRunner.hh
@@ -53,11 +53,6 @@ class GZ_SIM_GUI_VISIBLE GuiRunner : public QObject
   // Documentation inherited
   protected: bool eventFilter(QObject *_obj, QEvent *_event) override;
 
-  /// \brief Callback when a plugin has been added.
-  /// This function has no effect and is left here for ABI compatibility.
-  /// \param[in] _objectName Plugin's object name.
-  public slots: void OnPluginAdded(const QString &_objectName);
-
   /// \brief Make a new state request to the server.
   public slots: void RequestState();
 
@@ -75,7 +70,6 @@ class GZ_SIM_GUI_VISIBLE GuiRunner : public QObject
   private: Q_INVOKABLE void OnStateQt(const msgs::SerializedStepMap &_msg);
 
   /// \brief Update the plugins.
-  /// \todo(anyone) Move to GuiRunner::Implementation when porting to v5
   private: Q_INVOKABLE void UpdatePlugins();
 
   /// \brief Load systems