diff --git a/src/cheat_gui.cpp b/src/cheat_gui.cpp
index 6959689b22..abb8445be6 100644
--- a/src/cheat_gui.cpp
+++ b/src/cheat_gui.cpp
@@ -125,6 +125,7 @@ static int32 ClickChangeDateCheat(int32 p1, int32 p2)
 	EnginesMonthlyLoop();
 	SetWindowDirty(WC_STATUS_BAR, 0);
 	InvalidateWindowClassesData(WC_BUILD_STATION, 0);
+	InvalidateWindowClassesData(WC_BUILD_OBJECT, 0);
 	ResetSignalVariant();
 	return _cur_year;
 }