--- a/mozilla/b2g_project_branches.py
+++ b/mozilla/b2g_project_branches.py
@@ -44,17 +44,16 @@ PROJECT_BRANCHES = {
             'linux64_gecko-debug': {},
             'linux64-mulet': {},
         },
     },
     'ash': {
         'mozharness_repo_path': 'build/ash-mozharness',
         'mozharness_repo': 'https://hg.mozilla.org/build/ash-mozharness',
         'mozharness_tag': 'default',
-        'use_mozharness_repo_cache': False,
     },
     # Not needed on Birch at the moment, bug 977420.
     #'birch': {},
     'cedar': {
         'mozharness_tag': 'default',
     },
     'cypress': {
         'mozharness_tag': 'default',

--- a/mozilla/config.py
+++ b/mozilla/config.py
@@ -35,17 +35,17 @@ GLOBAL_VARS = {
     'balrog_credentials_file': 'BuildSlaves.py',
     'hg_username': 'ffxbld',
     'hg_ssh_key': '~cltbld/.ssh/ffxbld_rsa',
     'graph_selector': '/server/collect.cgi',
     'compare_locales_repo_path': 'build/compare-locales',
     'compare_locales_tag': 'RELEASE_AUTOMATION',
     'mozharness_repo_path': 'build/mozharness',
     'mozharness_tag': 'production',
-    'use_mozharness_repo_cache': True,  # ash overwrites this
+    'use_mozharness_repo_cache': True,
     'multi_locale_merge': True,
     'default_build_space': 5,
     'default_l10n_space': 3,
     'default_clobber_time': 24*7,  # 1 week
     'unittest_suites': [
         ('mochitest', dict(suite='mochitest-plain', chunkByDir=4, totalChunks=5)),
         ('mochitest-browser-chrome', ['mochitest-browser-chrome']),
         ('mochitest-other', ['mochitest-chrome', 'mochitest-a11y', 'mochitest-ipcplugins']),

--- a/mozilla/project_branches.py
+++ b/mozilla/project_branches.py
@@ -94,17 +94,16 @@ PROJECT_BRANCHES = {
     # 'alder': {},
     'ash': {
         'enable_perproduct_builds': False,
         'desktop_mozharness_repacks_enabled': True,
         'enable_nightly': True,
         'create_snippet': True,
         'create_partial': True,
         'create_mobile_snippet': True,
-        'use_mozharness_repo_cache': False,
         'lock_platforms': True,
         'script_repo_manifest': \
              "https://hg.mozilla.org/%(repo_path)s/raw-file/" + \
              "%(revision)s/testing/mozharness/mozharness.json",
         'talos_suites': {
             'xperf': 1,
         },
         'platforms': {