diff --git a/gstlal-burst/python/fxtools/multichannel_datasource.py b/gstlal-burst/python/fxtools/multichannel_datasource.py
index d94363211706fcd4aef723cc96c7936055aa55ff..54a8ddc0a9c4e1de23a69dfe9d1a2bf68268c063 100644
--- a/gstlal-burst/python/fxtools/multichannel_datasource.py
+++ b/gstlal-burst/python/fxtools/multichannel_datasource.py
@@ -466,7 +466,7 @@ class DataSourceInfo(object):
 		# FIXME: this is ugly, but we have to protect against busted shared memory partitions
 		if self.data_source == "lvshm":
 			import subprocess
-			subprocess.call(["smrepair", "-bufmode", "5", self.shm_part_dict[self.instrument]])
+			subprocess.call(["smrepair", "--bufmode", "5", self.shm_part_dict[self.instrument]])
 
 def append_options(parser):
 	"""!