diff --git a/mailman_sync.py b/mailman_sync.py
index aa0ed42..44623ed 100755
--- a/mailman_sync.py
+++ b/mailman_sync.py
@@ -17,6 +17,7 @@ Update Mailman 3 lists via a json API of the form:
 """
 
 import argparse
+import json
 import os
 import email.utils
 
@@ -120,12 +121,56 @@ def sync_moderators(
             list.remove_moderator(member.address)
 
 
+def update_cloudflare_lists(
+    dry_run: bool,
+    auth_token: str,
+    account_id: str,
+    script_name: str,
+    binding_name: str,
+    expected: list[str],
+):
+    settings_api_url = f"https://api.cloudflare.com/client/v4/accounts/{account_id}/workers/scripts/{script_name}/settings"
+
+    r = requests.get(
+        settings_api_url,
+        headers={"Authorization": auth_token},
+    )
+
+    data = r.json()
+    # TODO: more error handling
+    if not data["success"]:
+        print("Failed to fetch Cloudflare email worker settings")
+
+    bindings_dict = {b["name"]: b for b in data["result"]["bindings"]}
+    if set(bindings_dict.get(binding_name, {}).get("json", [])) != set(expected):
+        print("Cloudflare email worker list out of date, updating")
+        bindings_dict[binding_name] = {
+            "name": binding_name,
+            "json": expected,
+            "type": "json",
+        }
+        if not dry_run:
+            r = requests.patch(
+                settings_api_url,
+                headers={"Authorization": auth_token},
+                files={
+                    "settings": json.dumps({"bindings": list(bindings_dict.values())}),
+                },
+            )
+    else:
+        print("Cloudflare email worker list already up to date")
+
+
 def main(
     api: str,
     api_auth: str,
     mailman_client: mailmanclient.Client,
     dry_run: bool,
     mail_host: str,
+    cf_auth_token: str,
+    cf_account_id: str,
+    cf_script_name: str,
+    cf_binding_name: str,
 ):
     r = requests.get(api, headers={"Authorization": api_auth})
     if not r.ok:
@@ -155,10 +200,16 @@ def main(
             sync_moderators(list, dry_run, props["moderators"])
         sync_members(list, dry_run, props["members"])
 
+    lists = [list.list_name.lower() for list in domain.get_lists()]
+    update_cloudflare_lists(
+        dry_run, cf_auth_token, cf_account_id, cf_script_name, cf_binding_name, lists
+    )
+
 
 def parse_arguments():
     argp = argparse.ArgumentParser(description=__doc__)
     argp.add_argument("--api", required=True, help="API endpoint to retrieve JSON from")
+
     argp.add_argument("--mail-host", help="Base domain for all lists", required=True)
     argp.add_argument(
         "--mailman-url",
@@ -168,6 +219,24 @@ def parse_arguments():
     argp.add_argument(
         "--mailman-user", help="Username for Mailman3 REST API", default="restadmin"
     )
+
+    argp.add_argument(
+        "--cf-auth-token", help="Auth token for CloudFlare API", required=True
+    )
+    argp.add_argument(
+        "--cf-account-id",
+        help="Account ID of CloudFlare email worker script",
+        required=True,
+    )
+    argp.add_argument(
+        "--cf-script-name", help="Name of CloudFlare email worker script", required=True
+    )
+    argp.add_argument(
+        "--cf-binding-name",
+        help="Name of environment variable in email worker script",
+        default="MAILMAN_LISTS",
+    )
+
     argp.add_argument(
         "-n",
         "--dry-run",
@@ -197,4 +266,8 @@ if __name__ == "__main__":
         mailman_client,
         args.dry_run,
         args.mail_host,
+        args.cf_auth_token,
+        args.cf_account_id,
+        args.cf_script_name,
+        args.cf_binding_name,
     )