diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
index 7d6c541cbc..cf10d4824f 100644
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -1482,6 +1482,11 @@ public:
 		this->OnInvalidateData();
 	}
 
+	~BuildSignalWindow()
+	{
+		_convert_signal_button = false;
+	}
+
 	virtual void SetStringParameters(int widget) const
 	{
 		switch (widget) {