--- a/testing/mozharness/configs/marionette/windows_taskcluster_config.py
+++ b/testing/mozharness/configs/marionette/windows_taskcluster_config.py
@@ -15,18 +15,18 @@ config = {
             sys.executable,
             os.path.join(os.path.dirname(sys.executable), 'Lib', 'site-packages', 'virtualenv.py')
         ],
         'mozinstall': ['build/venv/scripts/python', 'build/venv/scripts/mozinstall-script.py'],
         'tooltool.py': [sys.executable, os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')],
         'hg': os.path.join(os.environ['PROGRAMFILES'], 'Mercurial', 'hg')
     },
 
+    "proxxy": {},
     "find_links": [
-        "http://pypi.pvt.build.mozilla.org/pub",
         "http://pypi.pub.build.mozilla.org/pub",
     ],
     "pip_index": False,
 
     "default_actions": [
         'clobber',
         'download-and-extract',
         'create-virtualenv',

--- a/testing/mozharness/configs/mediatests/taskcluster_windows_config.py
+++ b/testing/mozharness/configs/mediatests/taskcluster_windows_config.py
@@ -15,18 +15,18 @@ config = {
         'virtualenv': [
             sys.executable,
             os.path.join(os.path.dirname(sys.executable), 'Lib', 'site-packages', 'virtualenv.py')
         ],
         'mozinstall': ['build/venv/scripts/python', 'build/venv/scripts/mozinstall-script.py'],
         'tooltool.py': [sys.executable, os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')],
         'hg': os.path.join(os.environ['PROGRAMFILES'], 'Mercurial', 'hg')
     },
+    "proxxy": {},
     "find_links": [
-        "http://pypi.pvt.build.mozilla.org/pub",
         "http://pypi.pub.build.mozilla.org/pub",
     ],
     "pip_index": False,
 
     "default_actions": [
         'clobber',
         'download-and-extract',
         'create-virtualenv',

--- a/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
+++ b/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
@@ -23,18 +23,18 @@ config = {
     },
     ###
     "installer_path": INSTALLER_PATH,
     "binary_path": BINARY_PATH,
     "xpcshell_name": XPCSHELL_NAME,
     "virtualenv_path": 'venv',
     "virtualenv_python_dll": os.path.join(os.path.dirname(sys.executable), "python27.dll"),
 
+    "proxxy": {},
     "find_links": [
-        "http://pypi.pvt.build.mozilla.org/pub",
         "http://pypi.pub.build.mozilla.org/pub",
     ],
     "pip_index": False,
     "exe_suffix": EXE_SUFFIX,
     "run_file_names": {
         "mochitest": "runtests.py",
         "reftest": "runreftest.py",
         "xpcshell": "runxpcshelltests.py",

--- a/testing/mozharness/configs/web_platform_tests/prod_config_windows_taskcluster.py
+++ b/testing/mozharness/configs/web_platform_tests/prod_config_windows_taskcluster.py
@@ -26,18 +26,18 @@ config = {
             sys.executable,
             os.path.join(os.path.dirname(sys.executable), 'Lib', 'site-packages', 'virtualenv.py')
         ],
         'mozinstall': ['build/venv/scripts/python', 'build/venv/scripts/mozinstall-script.py'],
         'tooltool.py': [sys.executable, os.path.join(os.environ['MOZILLABUILD'], 'tooltool.py')],
         'hg': os.path.join(os.environ['PROGRAMFILES'], 'Mercurial', 'hg')
     },
 
+    "proxxy": {},
     "find_links": [
-        "http://pypi.pvt.build.mozilla.org/pub",
         "http://pypi.pub.build.mozilla.org/pub",
     ],
 
     "pip_index": False,
 
     "default_blob_upload_servers": [
          "https://blobupload.elasticbeanstalk.com",
     ],