diff --git a/CHANGELOG.md b/CHANGELOG.md
index 76bc3351..907a820d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,45 @@
-## Next release
+## 0.16.0-alpha.0 / 2018-09-18
 
+This release introduces a new API v2, fully generated via the OpenAPI project
+[1]. At the same time with this release the previous API v1 is being
+deprecated. API v1 will be removed with Alertmanager release v0.18.0.
+
+* [CHANGE] Deprecate API v1
+* [CHANGE] Remove `api/v1/alerts/groups` GET endpoint (#1508 & #1525)
 * [CHANGE] Revert Alertmanager working directory changes in Docker image back to `/alertmanager` (#1435)
-* [CHANGE] Remove `api/v1/alerts/groups` GET endpoint (#1508)
+* [CHANGE] Using the recommended label syntax for maintainer in Dockerfile (#1533)
+* [CHANGE] Change `alertmanager_notifications_total` to count attempted notifications, not only successful ones (#1578)
+* [CHANGE] Run as nobody inside container (#1586)
+* [CHANGE] Support `w` for weeks when creating silences, remove `y` for year (#1620)
+* [FEATURE] Introduce OpenAPI generated API v2 (#1352)
+* [FEATURE] Lookup parts in strings using regexp.MatchString in templates (#1452)
+* [FEATURE] Support image/thumb url in attachment in Slack notifier (#1506)
+* [FEATURE] Support custom TLS certificates for the email notifier (#1528)
+* [FEATURE] Add support for images and links in the PagerDuty notification config (#1559)
+* [FEATURE] Add support for grouping by all labels (#1588)
+* [FEATURE] [amtool] Add timeout support to amtool commands (#1471)
 * [FEATURE] [amtool] Added `config routes` tools for vizualization and testing routes (#1511)
+* [FEATURE] [amtool] Support adding alerts using amtool (#1461)
+* [ENHANCEMENT] Add help link in UI to Alertmanager documentation (#1522)
+* [ENHANCEMENT] Enforce HTTP or HTTPS URLs in Alertmanager config (#1567)
+* [ENHANCEMENT] Make OpsGenie API Key a templated string (#1594)
+* [ENHANCEMENT] Add name, value and SlackConfirmationField to action in Slack notifier (#1557)
+* [ENHANCEMENT] Show more alert information on silence form and silence view pages (#1601)
+* [ENHANCEMENT] Add cluster peers DNS refresh job (#1428)
+* [BUGFIX] Fix email template typo in alert-warning style (#1421)
+* [BUGFIX] Fix silence redirect on silence creation UI page (#1548)
+* [BUGFIX] Add missing `callback_id` parameter in Slack notifier (#1592)
+* [BUGFIX] Throw error if no auth mechanism matches in email notifier (#1608)
+* [BUGFIX] Use quoted-printable transfer encoding for the email notifier (#1609)
+* [BUGFIX] Do not merge expired gossip messages (#1631)
+* [BUGFIX] Fix "PLAIN" auth during notification via smtp-over-tls on port 465 (#1591)
+* [BUGFIX] [amtool] Support assuming first label is alertname in alert query with matchers (#1575)
+* [BUGFIX] [amtool] Fix config path check in amtool (#1538)
+* [BUGFIX] [amtool] Fix rfc3339 example texts (#1526)
 * [BUGFIX] [amtool] Fixed issue with loading path of a default configs (#1529)
 
+[1] https://github.com/prometheus/alertmanager#api
+
 ## 0.15.3 / 2018-11-09
 
 * [BUGFIX] Fix alert merging supporting both empty and set EndsAt property for firing alerts send by Prometheus (#1611)
diff --git a/VERSION b/VERSION
index 1985d914..39c1583d 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.15.3
+0.16.0-alpha.0