diff --git a/xfel_calibrate/calibrate.py b/xfel_calibrate/calibrate.py
index 9ca0315a27f3b4a2cfe8ba6c70cbd5d9cae9d193..a5e552ff86e68ac3b58610a68a4e6960c31e387f 100755
--- a/xfel_calibrate/calibrate.py
+++ b/xfel_calibrate/calibrate.py
@@ -377,7 +377,7 @@ def add_args_from_nb(nb, parser, cvar=None, overwrite_reqs=False):
                 ltype = p.type
 
             range_allowed = "RANGE ALLOWED" in p.comment.upper() if p.comment else False
-            pars_group.add_argument("--{}".format(consolize_name(p.name)),
+            pars_group.add_argument(f"--{consolize_name(p.name)}",
                                     nargs='+',
                                     type=ltype if not range_allowed else str,
                                     default=default,
@@ -387,18 +387,18 @@ def add_args_from_nb(nb, parser, cvar=None, overwrite_reqs=False):
         elif p.type == bool:
             # For a boolean, make --XYZ and --no-XYZ options.
             alt_group = pars_group.add_mutually_exclusive_group(required=required)
-            alt_group.add_argument("--no-{}".format(consolize_name(p.name)),
-                                   action="store_false",
+            alt_group.add_argument(f"--{consolize_name(p.name)}",
+                                   action="store_true",
                                    default=default,
                                    help=helpstr,
                                    dest=p.name)
-            alt_group.add_argument("--{}".format(consolize_name(p.name)),
-                                   action="store_true",
+            alt_group.add_argument(f"--no-{consolize_name(p.name)}",
+                                   action="store_false",
                                    default=default,
-                                   help=helpstr,
+                                   help=f"Opposite of --{consolize_name(p.name)}",
                                    dest=p.name)
         else:
-            pars_group.add_argument("--{}".format(consolize_name(p.name)),
+            pars_group.add_argument(f"--{consolize_name(p.name)}",
                                     type=p.type,
                                     default=default,
                                     help=helpstr,