--- a/taskcluster/ci/test/tests.yml
+++ b/taskcluster/ci/test/tests.yml
@@ -123,17 +123,17 @@ firefox-ui-functional-local:
     docker-image: {"in-tree": "desktop1604-test"}
     mozharness:
         script: firefox_ui_tests/functional.py
         config:
             by-test-platform:
                 windows.*:
                     - firefox_ui_tests/taskcluster_windows.py
                 macosx.*:
-                    - firefox_ui_tests/taskcluster.py
+                    - firefox_ui_tests/taskcluster_macosx.py
                 linux.*:
                     - firefox_ui_tests/taskcluster.py
                     - remove_executables.py
         extra-options:
             - "--tag"
             - "local"
 
 firefox-ui-functional-remote:
@@ -145,17 +145,17 @@ firefox-ui-functional-remote:
     docker-image: {"in-tree": "desktop1604-test"}
     mozharness:
         script: firefox_ui_tests/functional.py
         config:
             by-test-platform:
                 windows.*:
                     - firefox_ui_tests/taskcluster_windows.py
                 macosx.*:
-                    - firefox_ui_tests/taskcluster.py
+                    - firefox_ui_tests/taskcluster_macosx.py
                 linux.*:
                     - firefox_ui_tests/taskcluster.py
                     - remove_executables.py
         extra-options:
             - "--tag"
             - "remote"
 
 geckoview:

new file mode 100644
--- /dev/null
+++ b/testing/mozharness/configs/firefox_ui_tests/taskcluster_macosx.py
@@ -0,0 +1,20 @@
+# Config file for firefox ui tests run via TaskCluster.
+
+
+config = {
+    "vcs_share_base": "/builds/hg-shared",
+
+    "exes": {
+        'python': '/tools/buildbot/bin/python',
+        'virtualenv': ['/tools/buildbot/bin/python', '/tools/misc-python/virtualenv.py'],
+        'tooltool.py': "/tools/tooltool.py",
+    },
+
+    "find_links": [
+        "http://pypi.pub.build.mozilla.org/pub",
+    ],
+    "pip_index": False,
+
+    "download_minidump_stackwalk": True,
+    "tooltool_cache": "/builds/tooltool_cache",
+}