diff --git a/landoapi/repos.py b/landoapi/repos.py
index 2869b307..b9386852 100644
--- a/landoapi/repos.py
+++ b/landoapi/repos.py
@@ -403,6 +403,15 @@ def phab_identifier(self) -> str | None:
             milestone_tracking_flag_template="cf_status_firefox_esr{milestone}",
             commit_flags=[DONTBUILD],
         ),
+        "esr128": Repo(
+            tree="mozilla-esr128",
+            short_name="esr128",
+            url="https://hg.mozilla.org/releases/mozilla-esr128",
+            access_group=SCM_ALLOW_DIRECT_PUSH,
+            approval_required=True,
+            milestone_tracking_flag_template="cf_status_firefox_esr{milestone}",
+            commit_flags=[DONTBUILD],
+        ),
     },
 }