diff --git a/testing/mozharness/mozharness/mozilla/testing/raptor.py b/testing/mozharness/mozharness/mozilla/testing/raptor.py
index 9d14d0f39346..943d2c3622e6 100644
--- a/testing/mozharness/mozharness/mozilla/testing/raptor.py
+++ b/testing/mozharness/mozharness/mozilla/testing/raptor.py
@@ -315,9 +315,10 @@ class Raptor(TestingMixin, MercurialScript, CodeCoverageMixin, AndroidMixin, Pyt
         }],
         [["--setpref"], {
             "action": "append",
+            "metavar": "PREF=VALUE",
             "dest": "extra_prefs",
             "default": [],
-            "help": "A preference to set. Must be a key-value pair separated by a ':'."
+            "help": "Set a browser preference. May be used multiple times."
         }],
         [["--cold"], {
             "action": "store_true",
diff --git a/testing/mozharness/mozharness/mozilla/testing/talos.py b/testing/mozharness/mozharness/mozilla/testing/talos.py
index e692ce1c4623..eddac01e222d 100755
--- a/testing/mozharness/mozharness/mozilla/testing/talos.py
+++ b/testing/mozharness/mozharness/mozilla/testing/talos.py
@@ -163,8 +163,8 @@ class Talos(TestingMixin, MercurialScript, TooltoolMixin,
             "metavar": "PREF=VALUE",
             "dest": "extra_prefs",
             "default": [],
-            "help": "Defines an extra user preference."}
-         ],
+            "help": "Set a browser preference. May be used multiple times.",
+         }],
     ] + testing_config_options + copy.deepcopy(code_coverage_config_options)
 
     def __init__(self, **kwargs):
diff --git a/testing/raptor/raptor/cmdline.py b/testing/raptor/raptor/cmdline.py
index c5efd2150589..c0e1985565e8 100644
--- a/testing/raptor/raptor/cmdline.py
+++ b/testing/raptor/raptor/cmdline.py
@@ -160,7 +160,8 @@ def create_parser(mach_interface=False):
     add_arg('--enable-fission', dest="enable_fission", action="store_true", default=False,
             help="Enable Fission (site isolation) in Gecko.")
     add_arg('--setpref', dest="extra_prefs", action="append", default=[],
-            help="A preference to set. Must be a key-value pair separated by a ':'.")
+            metavar="PREF=VALUE",
+            help="Set a browser preference. May be used multiple times.")
     if not mach_interface:
         add_arg('--run-local', dest="run_local", default=False, action="store_true",
                 help="Flag which indicates if Raptor is running locally or in production")
diff --git a/testing/talos/talos/cmdline.py b/testing/talos/talos/cmdline.py
index 14c09cfe7468..4d40ff52ea29 100644
--- a/testing/talos/talos/cmdline.py
+++ b/testing/talos/talos/cmdline.py
@@ -115,7 +115,7 @@ def create_parser(mach_interface=False):
                  " Currently used for xperf only.")
     add_arg('--setpref', action='append', default=[], dest="extraPrefs",
             metavar="PREF=VALUE",
-            help="defines an extra user preference")
+            help="Set a browser preference. May be used multiple times.")
     add_arg("--firstNonBlankPaint", action='store_true', dest="fnbpaint",
             help="Wait for firstNonBlankPaint event before recording the time")
     add_arg("--pdfPaint", action='store_true', dest="pdfpaint",