diff --git a/src/qudi/gui/terascan/terascan_gui.py b/src/qudi/gui/terascan/terascan_gui.py
index c99ba1e..a842227 100644
--- a/src/qudi/gui/terascan/terascan_gui.py
+++ b/src/qudi/gui/terascan/terascan_gui.py
@@ -112,6 +112,9 @@ def on_activate(self) -> None:
         self.__timer = QtCore.QTimer()
         self.__timer.setSingleShot(False)
         self.__timer.timeout.connect(self._update_plot)
+        
+        # Restore saved wavelengths:
+        self.sigSetWavelengths.emit(self._start_wavelength, self._stop_wavelength)
 
         # Show the main window and raise it above all others
         self.show()