diff --git a/python/lsst/ts/externalscripts/maintel/make_cbp_throughput_scan.py b/python/lsst/ts/externalscripts/maintel/make_cbp_throughput_scan.py
index 15e2a272..9d6eb714 100755
--- a/python/lsst/ts/externalscripts/maintel/make_cbp_throughput_scan.py
+++ b/python/lsst/ts/externalscripts/maintel/make_cbp_throughput_scan.py
@@ -425,7 +425,7 @@ async def setup_calibration(self):
             self.config.optical_configuration,
         )
 
-        self.laser_start_propagate()
+        await self.laser_start_propagate()
 
         await self.setup_electrometer(
             self.electrometer_cbp,