diff --git a/src/aare/gui/panels/scan_settings_panel.py b/src/aare/gui/panels/scan_settings_panel.py
index b28aa562..65a5e6b1 100644
--- a/src/aare/gui/panels/scan_settings_panel.py
+++ b/src/aare/gui/panels/scan_settings_panel.py
@@ -24,6 +24,7 @@ class ScanSettingsPanel(QWidget):
     dtz_move = Signal(float)
     # TODO min and max dtz is set by beamline add max
     MIN_DTZ = 108.0  # this is beamline dependent
+    transmission_updated = Signal(float)
 
     def __init__(
         self,
@@ -259,6 +260,7 @@ class ScanSettingsPanel(QWidget):
     @Slot(float)
     def set_transmission(self, v: float):
         self._transmission = v
+        self.transmission_updated.emit(self._transmission)
 
     @Slot()
     def reload_parameters(self):