diff --git a/src/gui/dialogs/multiplayer/mp_join_game.cpp b/src/gui/dialogs/multiplayer/mp_join_game.cpp
index 4f84fffd42bd..1f3e6bc13ef5 100644
--- a/src/gui/dialogs/multiplayer/mp_join_game.cpp
+++ b/src/gui/dialogs/multiplayer/mp_join_game.cpp
@@ -456,6 +456,12 @@ void mp_join_game::generate_side_list(window& window)
 				//
 				const auto handler = [this, side_num](bool& handled, bool& halt) {
 					show_flg_select(side_num);
+					// note: this function is called from a std::function object stored in the widget 
+					//       and show_flg_select which internally calls
+					//       show_dialog -> pump -> ... -> network_handler -> ... -> generate_side_list
+					//       might destroy that std::function object while it is executed, this means that
+					//       using the captured variables 'this' and 'side_num' after this will result in
+					//       unexpected behaviour or crashes.
 					handled = halt = true;
 				};