diff --git a/testing/talos/talos/config.py b/testing/talos/talos/config.py
index 1998d6e4e9a5..0a5ee634869c 100644
--- a/testing/talos/talos/config.py
+++ b/testing/talos/talos/config.py
@@ -19,7 +19,7 @@ class ConfigurationError(Exception):
 
 DEFAULTS = dict(
     # args to pass to browser
-    extra_args='',
+    extra_args=[],
     buildid='testbuildid',
     init_url='getInfo.html',
     env={'NO_EM_RESTART': '1'},
diff --git a/testing/talos/talos/ffsetup.py b/testing/talos/talos/ffsetup.py
index 299630e7702d..03e4f67507e0 100644
--- a/testing/talos/talos/ffsetup.py
+++ b/testing/talos/talos/ffsetup.py
@@ -174,7 +174,10 @@ class FFSetup(object):
                 'appname',
                 'firefox'),
             mozrunner.Runner)
-        args = [self.browser_config["extra_args"], self.browser_config["init_url"]]
+
+        args = list(self.browser_config["extra_args"])
+        args.append(self.browser_config["init_url"])
+
         runner = runner_cls(profile=self.profile_dir,
                             binary=self.browser_config["browser_path"],
                             cmdargs=args,
diff --git a/testing/talos/talos/run_tests.py b/testing/talos/talos/run_tests.py
index c0ce9901b7e8..b327df510a8f 100755
--- a/testing/talos/talos/run_tests.py
+++ b/testing/talos/talos/run_tests.py
@@ -122,11 +122,13 @@ def run_tests(config, browser_config):
         if not test.get('profile', False):
             test['profile'] = config.get('profile')
 
+    browser_config['extra_args'] = []
+
     # pass --no-remote to firefox launch, if --develop is specified
     # we do that to allow locally the user to have another running firefox
     # instance
     if browser_config['develop']:
-        browser_config['extra_args'] = '--no-remote'
+        browser_config['extra_args'].append('--no-remote')
 
     # Pass subtests filter argument via a preference
     if browser_config['subtests']: