diff --git a/release-controller/reconciler.py b/release-controller/reconciler.py
index 0106b6edb..2e278374b 100644
--- a/release-controller/reconciler.py
+++ b/release-controller/reconciler.py
@@ -161,11 +161,14 @@ def version_package_checksum(version: str) -> str:
         f"https://download.dfinity.systems/ic/{version}/guest-os/update-img/SHA256SUMS"
     )
     response = requests.get(hashurl, timeout=10)
-    checksum = [
-        line
-        for line in response.content.decode("utf-8").splitlines()
-        if line.strip().endswith("update-img.tar.zst")
-    ][0].split(" ")[0]
+    checksum = typing.cast(
+        str,
+        [
+            line
+            for line in response.content.decode("utf-8").splitlines()
+            if line.strip().endswith("update-img.tar.zst")
+        ][0].split(" ")[0],
+    )
 
     for u in version_package_urls(version):
         LOGGER.getChild("version_package_checksum").debug("fetching package %s", u)
@@ -190,16 +193,6 @@ class ReplicaVersionProposalProvider(typing.Protocol):
     def replica_version_proposals(self) -> dict[str, int]: ...
 
 
-class SlackAnnouncerProtocol(typing.Protocol):
-    def announce_release(
-        self,
-        slack_url: str,
-        version_name: str,
-        google_doc_url: str,
-        tag_all_teams: bool,
-    ) -> None: ...
-
-
 class Reconciler:
     """Reconcile the state of the network with the release index, and create a forum post if needed."""
 
@@ -215,7 +208,7 @@ def __init__(
         active_version_provider: ActiveVersionProvider,
         replica_version_proposal_provider: ReplicaVersionProposalProvider,
         dre: dre_cli.DRECli,
-        slack_announcer: SlackAnnouncerProtocol,
+        slack_announcer: slack_announce.SlackAnnouncerProtocol,
         ignore_releases: list[str] | None = None,
     ):
         """Create a new reconciler."""
@@ -481,7 +474,7 @@ def main() -> None:
     )
     ic_repo = (
         GitRepo(
-            f"https://oauth2:{os.environ["GITHUB_TOKEN"]}@github.com/dfinity/ic.git",
+            f"https://oauth2:{os.environ['GITHUB_TOKEN']}@github.com/dfinity/ic.git",
             main_branch="master",
         )
         if not dry_run
@@ -512,7 +505,7 @@ def main() -> None:
         dre.get_past_election_proposals(),
     )
     slack_announcer = (
-        slack_announce.announce_release if not dry_run else dryrun.MockSlackAnnouncer()
+        slack_announce.SlackAnnouncer() if not dry_run else dryrun.MockSlackAnnouncer()
     )
 
     reconciler = Reconciler(
diff --git a/release-controller/slack_announce.py b/release-controller/slack_announce.py
index b6254f377..b8631ca79 100644
--- a/release-controller/slack_announce.py
+++ b/release-controller/slack_announce.py
@@ -3,14 +3,40 @@
 from dotenv import load_dotenv
 from slack_sdk.http_retry.handler import RetryHandler
 from slack_sdk.webhook import WebhookClient
+import typing
 
 from release_notes import RELEASE_NOTES_REVIEWERS
 
 
-def announce_release(slack_url, version_name, google_doc_url, tag_all_teams):
-    slack = WebhookClient(url=slack_url, retry_handlers=[RetryHandler(max_retry_count=2)])
+class SlackAnnouncerProtocol(typing.Protocol):
+    def announce_release(
+        self,
+        slack_url: str,
+        version_name: str,
+        google_doc_url: str,
+        tag_all_teams: bool,
+    ) -> None: ...
+
+
+class SlackAnnouncer(SlackAnnouncerProtocol):
+    def announce_release(
+        self, webhook: str, version_name: str, google_doc_url: str, tag_all_teams: bool
+    ) -> None:
+        announce_release_on_slack(webhook, version_name, google_doc_url, tag_all_teams)
+
+
+def announce_release_on_slack(slack_url, version_name, google_doc_url, tag_all_teams):
+    slack = WebhookClient(
+        url=slack_url, retry_handlers=[RetryHandler(max_retry_count=2)]
+    )
     notify_line = (
-        " ".join([f"<!subteam^{t.slack_id}>" for t in RELEASE_NOTES_REVIEWERS if t.send_announcement])
+        " ".join(
+            [
+                f"<!subteam^{t.slack_id}>"
+                for t in RELEASE_NOTES_REVIEWERS
+                if t.send_announcement
+            ]
+        )
         if tag_all_teams
         else "everyone"
     )
@@ -26,13 +52,13 @@ def announce_release(slack_url, version_name, google_doc_url, tag_all_teams):
 def main():
     load_dotenv()
 
-    announce_release(
+    announce_release_on_slack(
         os.environ["SLACK_WEBHOOK_URL"],
         "release-2024-03-06_23-01-base",
         "https://docs.google.com/document/d/1gCPmYxoq9_IccdChRzjoblAggTOdZ_IfTMukRbODO1I/edit#heading=h.7dcpz3fj7xrh",
         True,
     )
-    announce_release(
+    announce_release_on_slack(
         os.environ["SLACK_WEBHOOK_URL"],
         "release-2024-03-06_23-01-p2p",
         "https://docs.google.com/document/d/1gCPmYxoq9_IccdChRzjoblAggTOdZ_IfTMukRbODO1I/edit#heading=h.7dcpz3fj7xrh",
diff --git a/release-index.yaml b/release-index.yaml
index d72897df2..8a0a3c03e 100644
--- a/release-index.yaml
+++ b/release-index.yaml
@@ -1,5 +1,11 @@
 releases:
   # NOTE: Make sure to mark security hotfixes with the `security_fix: true` flag.
+  - rc_name: rc--2025-01-16_16-18
+    versions:
+      # Qualification pipeline:
+      # https://github.com/dfinity/ic/actions/runs/12813102877
+      - name: base
+        version: 233c1ee2ef68c1c8800b8151b2b9f38e17b8440a
   - rc_name: rc--2025-01-09_03-19
     versions:
       # Qualification pipeline: