--- a/testing/mozharness/mozharness/mozilla/l10n/locales.py
+++ b/testing/mozharness/mozharness/mozilla/l10n/locales.py
@@ -175,18 +175,18 @@ class LocalesMixin(ChunkingMixin):
             dirs['abs_l10n_dir'] = os.path.join(dirs['abs_work_dir'],
                                                 c['l10n_dir'])
         if 'mozilla_dir' in c:
             dirs['abs_mozilla_dir'] = os.path.join(dirs['abs_work_dir'],
                                                    c['mozilla_dir'])
             dirs['abs_locales_src_dir'] = os.path.join(dirs['abs_mozilla_dir'],
                                                        c['locales_dir'])
             dirs['abs_compare_locales_dir'] = os.path.join(dirs['abs_mozilla_dir'],
-                                                           'python', 'compare-locales',
-                                                           'compare_locales')
+                                                           'third_party', 'python',
+                                                           'compare-locales', 'compare_locales')
         else:
             # Use old-compare-locales if no mozilla_dir set, needed
             # for clobberer, and existing mozharness tests.
             dirs['abs_compare_locales_dir'] = os.path.join(dirs['abs_work_dir'],
                                                            'compare-locales')
 
         if 'objdir' in c:
             if os.path.isabs(c['objdir']):