diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
index 6b6e042804..7726417b4a 100644
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -174,6 +174,7 @@ struct AIListWindow : public Window {
 		}
 		InvalidateWindowData(WC_GAME_OPTIONS, WN_GAME_OPTIONS_AI);
 		InvalidateWindowClassesData(WC_AI_SETTINGS);
+		DeleteWindowByClass(WC_QUERY_STRING);
 	}
 
 	virtual void OnClick(Point pt, int widget, int click_count)