diff --git a/artiq/frontend/lda_controller.py b/artiq/frontend/lda_controller.py
index e96151bab..486313d36 100755
--- a/artiq/frontend/lda_controller.py
+++ b/artiq/frontend/lda_controller.py
@@ -9,10 +9,10 @@ from artiq.tools import verbosity_args, simple_network_args, init_logger
 
 def get_argparser():
     parser = argparse.ArgumentParser()
-    parser.add_argument('-d', '--device', default="LDA-102",
+    parser.add_argument("-d", "--device", default="LDA-102",
                         choices=["LDA-102", "LDA-602", "sim"])
     simple_network_args(parser, 3253)
-    parser.add_argument('-s', '--serial', default=None,
+    parser.add_argument("-s", "--serial", default=None,
                         help="USB serial number of the device")
     verbosity_args(parser)
     return parser