--- a/mozilla/config.py
+++ b/mozilla/config.py
@@ -2835,16 +2835,21 @@ for branch in BRANCHES.keys():
 
 # Bug 1379789- disable buildbot windows builds on date
 for name, branch in [('date', BRANCHES['date'])]:
     for platform in branch['platforms'].keys():
         if not platform.startswith('win'):
             continue
         del branch['platforms'][platform]
 
+# Support cross-channel l10n in 57+ -- Bug 1397721
+for name, branch in items_at_least(BRANCHES, 'gecko_version', 57):
+    if 'l10n_repo_path' not in branch:
+        continue
+    branch['l10n_repo_path'] = 'l10n-central'
 
 if __name__ == "__main__":
     import sys
     import pprint
     args = sys.argv[1:]
 
     if len(args) > 0:
         items = dict([(b, BRANCHES[b]) for b in args])

--- a/mozilla/thunderbird_config.py
+++ b/mozilla/thunderbird_config.py
@@ -959,16 +959,21 @@ BRANCHES['cypress']['unittest_build_spac
 BRANCHES['cypress']['mozilla_srcdir'] = None
 
 # Bug 1322402 - mac universal builds dropped at 53, keep using the universal mozconfig and objdir before then
 for name, branch in items_before(BRANCHES, 'gecko_version', 53):
     if 'macosx64' in branch['platforms']:
         branch['platforms']['macosx64']['src_mozconfig'] = 'mail/config/mozconfigs/macosx-universal/nightly'
         branch['platforms']['macosx64']['platform_objdir'] = '%s/i386' % OBJDIR
 
+# Support cross-channel l10n in 57+ -- Bug 1397721
+for name, branch in items_at_least(BRANCHES, 'gecko_version', 57):
+    if 'l10n_repo_path' not in branch:
+        continue
+    branch['l10n_repo_path'] = 'l10n-central'
 
 if __name__ == "__main__":
     import sys
     import pprint
     args = sys.argv[1:]
 
     if len(args) > 0:
         items = dict([(b, BRANCHES[b]) for b in args])